Alright, thanks for all the help guys, and I finally managed to:

Install the xpak thingie.
Ran it
Deleted the .pak files
Installed the MOD


Except now when I try to run it, at first the game would open up but when it got to the first screen(The one with the Phalanx getting shot at), the game just stops and it closes...Is there a way I can fix this?