Double-click the file, if your installation of ut2003 doesn't recognize the file or you have other problems installing please check this webpage:
http://wiki.beyondunreal.com/wiki?action=browse&id=UMOD/Problems&oldid=UT2MOD/Problems
If you all ready have UnrealSpeed installed, I suggest you deinstall it first
before installing this version, sorry, to much has changed including the
settings headers.
Run it by starting:
Start menu - Programs - Unrealspeed - Play Unrealspeed