OK:
1: Install UT2003.
2: If you want to play online, patch it to the latest version.
3: Download YOUR versions crack from GCW.
4: Extract the crack with
WinRAR
5: Copy the crack over to your installed directory. Default is c:\\ut2003\system.
6: You will be prompted a file already exsists with that filename, do you want to replace it? well of course you do.
7: Play the game.