Yeah, yeah, but some files in some games just won't work with just their names switched.
Besides, if this is hacking then I am little green man from mars. Hacking is something else then just changing filenames and bragging about how much effective that was.
See example here. Now go learn something about hexadecimals and return when you're done. Modifying hexadecimal data strains is very effective, but can be also dangerous if you do something wrong...
Plus, naturally, it's a s***load of fun to figure out which part of the file does what.