Ok, so they may be in different directories, but it’s still a hell of a lot easier to replace four files than the backup and reinstall the whole damn system. It should be possible to create a zip with the relevant number of directories with the files in them, so that when one uploads the set of directories, the FTP sees that they exist and says, “hey, there’s already a file here with this name, want to replace it or keep it? this directory already exists and. . . has a file with this name, want to replace it or keep it, or make a new directory?” and so on. Most FTP clients I’ve used are smart enough for that. . . . And failing that, most users who have enough technical knowledge to have installed the damn system in the first place are knowledgeable enough to upload four files.
So again, why isn’t it possible to just replace the four affected files?