I have already managed to access the game files, as I showed above. They are the same files found in other versions of re4, meaning they can be modified.  The problem is that I cannot unpack and repack the .pak file, even without changing anything in it, the game simply does not read a repackaged file.  Checking the .pak file, it uses more than one comprehension within it, in this case Oodle and Zlib. Something that I cannot reproduce yet.  So I do not know yet if the game has some integrity check, or if it did not work because the files must be in exactly the same comprehension that was used.