If you installed UnWheel with the EXE installer, you will find an Uninstall in Windows' Add/Remove programs option.
If you installed with the zip version, just delete:
Code:
Maps\UW*.ut2
Textures\UW*.utx
Textures\UnWheel*.utx
Sounds\UnWheel*.uax
StaticMeshes\UnWheel*.usx
StaticMeshes\UW*.usx
System\UnWheel*.*
Or, use Windows' Find Files option, and in your UT2004 directory, search for the following (you can then delete the files and directories it finds):
Using the above method, DO NOT delete the files named
UWeb.* as they are UT2004 files required to run the game.