Nope! You can simply unpack it with WinZip. It has nothing to do with IS6 cab files so i6comp is not needed. Extract the files to a directory you want, replace the exe (with a crack, I guess
) and zip them together. Where's the problem?
BTW: I don't know a programm which can replace files in a zipped exe archive. Maybe I have to write one? Hmm... but I guess I'm to lazy