How to handle removed files
See this SE question
A file was removed from the installation tarball but the Joomla upgrade process installs into existing directories meaning the 'removed' file was still present. In this case, it caused the upgrade to fail and will cause problems for any Joomla upgrades following the documented method.
More generally, the same problem applies to any files no longer included in releases.
- in the release notes say that files have been removed so don't follow the normal upgrade process
- add an upgrade step that removes old files (but note this problem occurred early in the upgrade process)
- change the upgrade instructions for Joomla