diff --git a/scripts/Android.bp b/scripts/Android.bp
index 8a76203..b20533a 100644
--- a/scripts/Android.bp
+++ b/scripts/Android.bp
@@ -29,7 +29,6 @@
         "update_payload/__init__.py",
         "update_payload/payload.py",
         "update_payload/checker.py",
-        "update_payload/applier.py",
         "update_payload/common.py",
         "update_payload/error.py",
         "update_payload/histogram.py",
diff --git a/scripts/update_payload/applier.py b/scripts/update_payload/applier.py
deleted file mode 100644
index 29ccb8e..0000000
--- a/scripts/update_payload/applier.py
+++ /dev/null
@@ -1,621 +0,0 @@
-#
-# Copyright (C) 2013 The Android Open Source Project
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-
-"""Applying a Chrome OS update payload.
-
-This module is used internally by the main Payload class for applying an update
-payload. The interface for invoking the applier is as follows:
-
-  applier = PayloadApplier(payload)
-  applier.Run(...)
-
-"""
-
-from __future__ import absolute_import
-from __future__ import print_function
-
-import array
-import bz2
-import hashlib
-# Not everywhere we can have the lzma library so we ignore it if we didn't have
-# it because it is not going to be used. For example, 'cros flash' uses
-# devserver code which eventually loads this file, but the lzma library is not
-# included in the client test devices, and it is not necessary to do so. But
-# lzma is not used in 'cros flash' so it should be fine. Python 3.x include
-# lzma, but for backward compatibility with Python 2.7, backports-lzma is
-# needed.
-try:
-  import lzma
-except ImportError:
-  try:
-    from backports import lzma
-  except ImportError:
-    pass
-import os
-import subprocess
-import sys
-import tempfile
-
-from update_payload import common
-from update_payload.error import PayloadError
-
-#
-# Helper functions.
-#
-def _VerifySha256(file_obj, expected_hash, name, length=-1):
-  """Verifies the SHA256 hash of a file.
-
-  Args:
-    file_obj: file object to read
-    expected_hash: the hash digest we expect to be getting
-    name: name string of this hash, for error reporting
-    length: precise length of data to verify (optional)
-
-  Raises:
-    PayloadError if computed hash doesn't match expected one, or if fails to
-    read the specified length of data.
-  """
-  hasher = hashlib.sha256()
-  block_length = 1024 * 1024
-  max_length = length if length >= 0 else sys.maxsize
-
-  while max_length > 0:
-    read_length = min(max_length, block_length)
-    data = file_obj.read(read_length)
-    if not data:
-      break
-    max_length -= len(data)
-    hasher.update(data)
-
-  if length >= 0 and max_length > 0:
-    raise PayloadError(
-        'insufficient data (%d instead of %d) when verifying %s' %
-        (length - max_length, length, name))
-
-  actual_hash = hasher.digest()
-  if actual_hash != expected_hash:
-    raise PayloadError('%s hash (%s) not as expected (%s)' %
-                       (name, common.FormatSha256(actual_hash),
-                        common.FormatSha256(expected_hash)))
-
-
-def _ReadExtents(file_obj, extents, block_size, max_length=-1):
-  """Reads data from file as defined by extent sequence.
-
-  This tries to be efficient by not copying data as it is read in chunks.
-
-  Args:
-    file_obj: file object
-    extents: sequence of block extents (offset and length)
-    block_size: size of each block
-    max_length: maximum length to read (optional)
-
-  Returns:
-    A character array containing the concatenated read data.
-  """
-  data = array.array('B')
-  if max_length < 0:
-    max_length = sys.maxsize
-  for ex in extents:
-    if max_length == 0:
-      break
-    read_length = min(max_length, ex.num_blocks * block_size)
-
-    file_obj.seek(ex.start_block * block_size)
-    data.fromfile(file_obj, read_length)
-
-    max_length -= read_length
-
-  return data
-
-
-def _WriteExtents(file_obj, data, extents, block_size, base_name):
-  """Writes data to file as defined by extent sequence.
-
-  This tries to be efficient by not copy data as it is written in chunks.
-
-  Args:
-    file_obj: file object
-    data: data to write
-    extents: sequence of block extents (offset and length)
-    block_size: size of each block
-    base_name: name string of extent sequence for error reporting
-
-  Raises:
-    PayloadError when things don't add up.
-  """
-  data_offset = 0
-  data_length = len(data)
-  for ex, ex_name in common.ExtentIter(extents, base_name):
-    if not data_length:
-      raise PayloadError('%s: more write extents than data' % ex_name)
-    write_length = min(data_length, ex.num_blocks * block_size)
-    file_obj.seek(ex.start_block * block_size)
-    file_obj.write(data[data_offset:(data_offset + write_length)])
-
-    data_offset += write_length
-    data_length -= write_length
-
-  if data_length:
-    raise PayloadError('%s: more data than write extents' % base_name)
-
-
-def _ExtentsToBspatchArg(extents, block_size, base_name, data_length=-1):
-  """Translates an extent sequence into a bspatch-compatible string argument.
-
-  Args:
-    extents: sequence of block extents (offset and length)
-    block_size: size of each block
-    base_name: name string of extent sequence for error reporting
-    data_length: the actual total length of the data in bytes (optional)
-
-  Returns:
-    A tuple consisting of (i) a string of the form
-    "off_1:len_1,...,off_n:len_n", (ii) an offset where zero padding is needed
-    for filling the last extent, (iii) the length of the padding (zero means no
-    padding is needed and the extents cover the full length of data).
-
-  Raises:
-    PayloadError if data_length is too short or too long.
-  """
-  arg = ''
-  pad_off = pad_len = 0
-  if data_length < 0:
-    data_length = sys.maxsize
-  for ex, ex_name in common.ExtentIter(extents, base_name):
-    if not data_length:
-      raise PayloadError('%s: more extents than total data length' % ex_name)
-
-    start_byte = ex.start_block * block_size
-    num_bytes = ex.num_blocks * block_size
-    if data_length < num_bytes:
-      # We're only padding a real extent.
-      pad_off = start_byte + data_length
-      pad_len = num_bytes - data_length
-      num_bytes = data_length
-
-    arg += '%s%d:%d' % (arg and ',', start_byte, num_bytes)
-    data_length -= num_bytes
-
-  if data_length:
-    raise PayloadError('%s: extents not covering full data length' % base_name)
-
-  return arg, pad_off, pad_len
-
-
-#
-# Payload application.
-#
-class PayloadApplier(object):
-  """Applying an update payload.
-
-  This is a short-lived object whose purpose is to isolate the logic used for
-  applying an update payload.
-  """
-
-  def __init__(self, payload, bsdiff_in_place=True, bspatch_path=None,
-               puffpatch_path=None, truncate_to_expected_size=True):
-    """Initialize the applier.
-
-    Args:
-      payload: the payload object to check
-      bsdiff_in_place: whether to perform BSDIFF operation in-place (optional)
-      bspatch_path: path to the bspatch binary (optional)
-      puffpatch_path: path to the puffpatch binary (optional)
-      truncate_to_expected_size: whether to truncate the resulting partitions
-                                 to their expected sizes, as specified in the
-                                 payload (optional)
-    """
-    assert payload.is_init, 'uninitialized update payload'
-    self.payload = payload
-    self.block_size = payload.manifest.block_size
-    self.minor_version = payload.manifest.minor_version
-    self.bsdiff_in_place = bsdiff_in_place
-    self.bspatch_path = bspatch_path or 'bspatch'
-    self.puffpatch_path = puffpatch_path or 'puffin'
-    self.truncate_to_expected_size = truncate_to_expected_size
-
-  def _ApplyReplaceOperation(self, op, op_name, out_data, part_file, part_size):
-    """Applies a REPLACE{,_BZ,_XZ} operation.
-
-    Args:
-      op: the operation object
-      op_name: name string for error reporting
-      out_data: the data to be written
-      part_file: the partition file object
-      part_size: the size of the partition
-
-    Raises:
-      PayloadError if something goes wrong.
-    """
-    block_size = self.block_size
-    data_length = len(out_data)
-
-    # Decompress data if needed.
-    if op.type == common.OpType.REPLACE_BZ:
-      out_data = bz2.decompress(out_data)
-      data_length = len(out_data)
-    elif op.type == common.OpType.REPLACE_XZ:
-      # pylint: disable=no-member
-      out_data = lzma.decompress(out_data)
-      data_length = len(out_data)
-
-    # Write data to blocks specified in dst extents.
-    data_start = 0
-    for ex, ex_name in common.ExtentIter(op.dst_extents,
-                                         '%s.dst_extents' % op_name):
-      start_block = ex.start_block
-      num_blocks = ex.num_blocks
-      count = num_blocks * block_size
-
-      data_end = data_start + count
-
-      # Make sure we're not running past partition boundary.
-      if (start_block + num_blocks) * block_size > part_size:
-        raise PayloadError(
-            '%s: extent (%s) exceeds partition size (%d)' %
-            (ex_name, common.FormatExtent(ex, block_size),
-             part_size))
-
-      # Make sure that we have enough data to write.
-      if data_end >= data_length + block_size:
-        raise PayloadError(
-            '%s: more dst blocks than data (even with padding)')
-
-      # Pad with zeros if necessary.
-      if data_end > data_length:
-        padding = data_end - data_length
-        out_data += b'\0' * padding
-
-      self.payload.payload_file.seek(start_block * block_size)
-      part_file.seek(start_block * block_size)
-      part_file.write(out_data[data_start:data_end])
-
-      data_start += count
-
-    # Make sure we wrote all data.
-    if data_start < data_length:
-      raise PayloadError('%s: wrote fewer bytes (%d) than expected (%d)' %
-                         (op_name, data_start, data_length))
-
-  def _ApplyZeroOperation(self, op, op_name, part_file):
-    """Applies a ZERO operation.
-
-    Args:
-      op: the operation object
-      op_name: name string for error reporting
-      part_file: the partition file object
-
-    Raises:
-      PayloadError if something goes wrong.
-    """
-    block_size = self.block_size
-    base_name = '%s.dst_extents' % op_name
-
-    # Iterate over the extents and write zero.
-    # pylint: disable=unused-variable
-    for ex, ex_name in common.ExtentIter(op.dst_extents, base_name):
-      part_file.seek(ex.start_block * block_size)
-      part_file.write(b'\0' * (ex.num_blocks * block_size))
-
-  def _ApplySourceCopyOperation(self, op, op_name, old_part_file,
-                                new_part_file):
-    """Applies a SOURCE_COPY operation.
-
-    Args:
-      op: the operation object
-      op_name: name string for error reporting
-      old_part_file: the old partition file object
-      new_part_file: the new partition file object
-
-    Raises:
-      PayloadError if something goes wrong.
-    """
-    if not old_part_file:
-      raise PayloadError(
-          '%s: no source partition file provided for operation type (%d)' %
-          (op_name, op.type))
-
-    block_size = self.block_size
-
-    # Gather input raw data from src extents.
-    in_data = _ReadExtents(old_part_file, op.src_extents, block_size)
-
-    # Dump extracted data to dst extents.
-    _WriteExtents(new_part_file, in_data, op.dst_extents, block_size,
-                  '%s.dst_extents' % op_name)
-
-  def _BytesInExtents(self, extents, base_name):
-    """Counts the length of extents in bytes.
-
-    Args:
-      extents: The list of Extents.
-      base_name: For error reporting.
-
-    Returns:
-      The number of bytes in extents.
-    """
-
-    length = 0
-    # pylint: disable=unused-variable
-    for ex, ex_name in common.ExtentIter(extents, base_name):
-      length += ex.num_blocks * self.block_size
-    return length
-
-  def _ApplyDiffOperation(self, op, op_name, patch_data, old_part_file,
-                          new_part_file):
-    """Applies a SOURCE_BSDIFF, BROTLI_BSDIFF or PUFFDIFF operation.
-
-    Args:
-      op: the operation object
-      op_name: name string for error reporting
-      patch_data: the binary patch content
-      old_part_file: the source partition file object
-      new_part_file: the target partition file object
-
-    Raises:
-      PayloadError if something goes wrong.
-    """
-    if not old_part_file:
-      raise PayloadError(
-          '%s: no source partition file provided for operation type (%d)' %
-          (op_name, op.type))
-
-    block_size = self.block_size
-
-    # Dump patch data to file.
-    with tempfile.NamedTemporaryFile(delete=False) as patch_file:
-      patch_file_name = patch_file.name
-      patch_file.write(patch_data)
-
-    if (hasattr(new_part_file, 'fileno') and
-        ((not old_part_file) or hasattr(old_part_file, 'fileno'))):
-      # Construct input and output extents argument for bspatch.
-
-      in_extents_arg, _, _ = _ExtentsToBspatchArg(
-          op.src_extents, block_size, '%s.src_extents' % op_name,
-          data_length=op.src_length if op.src_length else
-          self._BytesInExtents(op.src_extents, "%s.src_extents"))
-      out_extents_arg, pad_off, pad_len = _ExtentsToBspatchArg(
-          op.dst_extents, block_size, '%s.dst_extents' % op_name,
-          data_length=op.dst_length if op.dst_length else
-          self._BytesInExtents(op.dst_extents, "%s.dst_extents"))
-
-      new_file_name = '/dev/fd/%d' % new_part_file.fileno()
-      # Diff from source partition.
-      old_file_name = '/dev/fd/%d' % old_part_file.fileno()
-
-      # In python3, file descriptors(fd) are not passed to child processes by
-      # default. To pass the fds to the child processes, we need to set the flag
-      # 'inheritable' in the fds and make the subprocess calls with the argument
-      # close_fds set to False.
-      if sys.version_info.major >= 3:
-        os.set_inheritable(new_part_file.fileno(), True)
-        os.set_inheritable(old_part_file.fileno(), True)
-
-      if op.type in (common.OpType.SOURCE_BSDIFF, common.OpType.BROTLI_BSDIFF):
-        # Invoke bspatch on partition file with extents args.
-        bspatch_cmd = [self.bspatch_path, old_file_name, new_file_name,
-                       patch_file_name, in_extents_arg, out_extents_arg]
-        subprocess.check_call(bspatch_cmd, close_fds=False)
-      elif op.type == common.OpType.PUFFDIFF:
-        # Invoke puffpatch on partition file with extents args.
-        puffpatch_cmd = [self.puffpatch_path,
-                         "--operation=puffpatch",
-                         "--src_file=%s" % old_file_name,
-                         "--dst_file=%s" % new_file_name,
-                         "--patch_file=%s" % patch_file_name,
-                         "--src_extents=%s" % in_extents_arg,
-                         "--dst_extents=%s" % out_extents_arg]
-        subprocess.check_call(puffpatch_cmd, close_fds=False)
-      else:
-        raise PayloadError("Unknown operation %s" % op.type)
-
-      # Pad with zeros past the total output length.
-      if pad_len:
-        new_part_file.seek(pad_off)
-        new_part_file.write(b'\0' * pad_len)
-    else:
-      # Gather input raw data and write to a temp file.
-      input_part_file = old_part_file if old_part_file else new_part_file
-      in_data = _ReadExtents(input_part_file, op.src_extents, block_size,
-                             max_length=op.src_length if op.src_length else
-                             self._BytesInExtents(op.src_extents,
-                                                  "%s.src_extents"))
-      with tempfile.NamedTemporaryFile(delete=False) as in_file:
-        in_file_name = in_file.name
-        in_file.write(in_data)
-
-      # Allocate temporary output file.
-      with tempfile.NamedTemporaryFile(delete=False) as out_file:
-        out_file_name = out_file.name
-
-      if op.type in (common.OpType.SOURCE_BSDIFF, common.OpType.BROTLI_BSDIFF):
-        # Invoke bspatch.
-        bspatch_cmd = [self.bspatch_path, in_file_name, out_file_name,
-                       patch_file_name]
-        subprocess.check_call(bspatch_cmd)
-      elif op.type == common.OpType.PUFFDIFF:
-        # Invoke puffpatch.
-        puffpatch_cmd = [self.puffpatch_path,
-                         "--operation=puffpatch",
-                         "--src_file=%s" % in_file_name,
-                         "--dst_file=%s" % out_file_name,
-                         "--patch_file=%s" % patch_file_name]
-        subprocess.check_call(puffpatch_cmd)
-      else:
-        raise PayloadError("Unknown operation %s" % op.type)
-
-      # Read output.
-      with open(out_file_name, 'rb') as out_file:
-        out_data = out_file.read()
-        if len(out_data) != op.dst_length:
-          raise PayloadError(
-              '%s: actual patched data length (%d) not as expected (%d)' %
-              (op_name, len(out_data), op.dst_length))
-
-      # Write output back to partition, with padding.
-      unaligned_out_len = len(out_data) % block_size
-      if unaligned_out_len:
-        out_data += b'\0' * (block_size - unaligned_out_len)
-      _WriteExtents(new_part_file, out_data, op.dst_extents, block_size,
-                    '%s.dst_extents' % op_name)
-
-      # Delete input/output files.
-      os.remove(in_file_name)
-      os.remove(out_file_name)
-
-    # Delete patch file.
-    os.remove(patch_file_name)
-
-  def _ApplyOperations(self, operations, base_name, old_part_file,
-                       new_part_file, part_size):
-    """Applies a sequence of update operations to a partition.
-
-    Args:
-      operations: the sequence of operations
-      base_name: the name of the operation sequence
-      old_part_file: the old partition file object, open for reading/writing
-      new_part_file: the new partition file object, open for reading/writing
-      part_size: the partition size
-
-    Raises:
-      PayloadError if anything goes wrong while processing the payload.
-    """
-    for op, op_name in common.OperationIter(operations, base_name):
-      # Read data blob.
-      data = self.payload.ReadDataBlob(op.data_offset, op.data_length)
-
-      if op.type in (common.OpType.REPLACE, common.OpType.REPLACE_BZ,
-                     common.OpType.REPLACE_XZ):
-        self._ApplyReplaceOperation(op, op_name, data, new_part_file, part_size)
-      elif op.type == common.OpType.ZERO:
-        self._ApplyZeroOperation(op, op_name, new_part_file)
-      elif op.type == common.OpType.SOURCE_COPY:
-        self._ApplySourceCopyOperation(op, op_name, old_part_file,
-                                       new_part_file)
-      elif op.type in (common.OpType.SOURCE_BSDIFF, common.OpType.PUFFDIFF,
-                       common.OpType.BROTLI_BSDIFF):
-        self._ApplyDiffOperation(op, op_name, data, old_part_file,
-                                 new_part_file)
-      else:
-        raise PayloadError('%s: unknown operation type (%d)' %
-                           (op_name, op.type))
-
-  def _ApplyToPartition(self, operations, part_name, base_name,
-                        new_part_file_name, new_part_info,
-                        old_part_file_name=None, old_part_info=None):
-    """Applies an update to a partition.
-
-    Args:
-      operations: the sequence of update operations to apply
-      part_name: the name of the partition, for error reporting
-      base_name: the name of the operation sequence
-      new_part_file_name: file name to write partition data to
-      new_part_info: size and expected hash of dest partition
-      old_part_file_name: file name of source partition (optional)
-      old_part_info: size and expected hash of source partition (optional)
-
-    Raises:
-      PayloadError if anything goes wrong with the update.
-    """
-    # Do we have a source partition?
-    if old_part_file_name:
-      # Verify the source partition.
-      with open(old_part_file_name, 'rb') as old_part_file:
-        _VerifySha256(old_part_file, old_part_info.hash,
-                      'old ' + part_name, length=old_part_info.size)
-      new_part_file_mode = 'r+b'
-      open(new_part_file_name, 'w').close()
-
-    else:
-      # We need to create/truncate the dst partition file.
-      new_part_file_mode = 'w+b'
-
-    # Apply operations.
-    with open(new_part_file_name, new_part_file_mode) as new_part_file:
-      old_part_file = (open(old_part_file_name, 'r+b')
-                       if old_part_file_name else None)
-      try:
-        self._ApplyOperations(operations, base_name, old_part_file,
-                              new_part_file, new_part_info.size)
-      finally:
-        if old_part_file:
-          old_part_file.close()
-
-      # Truncate the result, if so instructed.
-      if self.truncate_to_expected_size:
-        new_part_file.seek(0, 2)
-        if new_part_file.tell() > new_part_info.size:
-          new_part_file.seek(new_part_info.size)
-          new_part_file.truncate()
-
-    # Verify the resulting partition.
-    with open(new_part_file_name, 'rb') as new_part_file:
-      _VerifySha256(new_part_file, new_part_info.hash,
-                    'new ' + part_name, length=new_part_info.size)
-
-  def Run(self, new_parts, old_parts=None):
-    """Applier entry point, invoking all update operations.
-
-    Args:
-      new_parts: map of partition name to dest partition file
-      old_parts: map of partition name to source partition file (optional)
-
-    Raises:
-      PayloadError if payload application failed.
-    """
-    if old_parts is None:
-      old_parts = {}
-
-    self.payload.ResetFile()
-
-    new_part_info = {}
-    old_part_info = {}
-    install_operations = []
-
-    manifest = self.payload.manifest
-    for part in manifest.partitions:
-      name = part.partition_name
-      new_part_info[name] = part.new_partition_info
-      old_part_info[name] = part.old_partition_info
-      install_operations.append((name, part.operations))
-
-    part_names = set(new_part_info.keys())  # Equivalently, old_part_info.keys()
-
-    # Make sure the arguments are sane and match the payload.
-    new_part_names = set(new_parts.keys())
-    if new_part_names != part_names:
-      raise PayloadError('missing dst partition(s) %s' %
-                         ', '.join(part_names - new_part_names))
-
-    old_part_names = set(old_parts.keys())
-    if part_names - old_part_names:
-      if self.payload.IsDelta():
-        raise PayloadError('trying to apply a delta update without src '
-                           'partition(s) %s' %
-                           ', '.join(part_names - old_part_names))
-    elif old_part_names == part_names:
-      if self.payload.IsFull():
-        raise PayloadError('trying to apply a full update onto src partitions')
-    else:
-      raise PayloadError('not all src partitions provided')
-
-    for name, operations in install_operations:
-      # Apply update to partition.
-      self._ApplyToPartition(
-          operations, name, '%s_install_operations' % name, new_parts[name],
-          new_part_info[name], old_parts.get(name, None), old_part_info[name])
diff --git a/scripts/update_payload/payload.py b/scripts/update_payload/payload.py
index aa1127d..5fd47c1 100644
--- a/scripts/update_payload/payload.py
+++ b/scripts/update_payload/payload.py
@@ -27,7 +27,6 @@
 
 import update_metadata_pb2
 
-from update_payload import applier
 from update_payload import checker
 from update_payload import common
 from update_payload.error import PayloadError
@@ -305,30 +304,3 @@
                metadata_size=metadata_size,
                part_sizes=part_sizes,
                report_out_file=report_out_file)
-
-  def Apply(self, new_parts, old_parts=None, bsdiff_in_place=True,
-            bspatch_path=None, puffpatch_path=None,
-            truncate_to_expected_size=True):
-    """Applies the update payload.
-
-    Args:
-      new_parts: map of partition name to dest partition file
-      old_parts: map of partition name to partition file (optional)
-      bsdiff_in_place: whether to perform BSDIFF operations in-place (optional)
-      bspatch_path: path to the bspatch binary (optional)
-      puffpatch_path: path to the puffpatch binary (optional)
-      truncate_to_expected_size: whether to truncate the resulting partitions
-                                 to their expected sizes, as specified in the
-                                 payload (optional)
-
-    Raises:
-      PayloadError if payload application failed.
-    """
-    self._AssertInit()
-
-    # Create a short-lived payload applier object and run it.
-    helper = applier.PayloadApplier(
-        self, bsdiff_in_place=bsdiff_in_place, bspatch_path=bspatch_path,
-        puffpatch_path=puffpatch_path,
-        truncate_to_expected_size=truncate_to_expected_size)
-    helper.Run(new_parts, old_parts=old_parts)