Or put in the 3rd disk from the game and go to the Extras folder where you'll find the original skin art all ready to go in PNG format
When you're done editing the skin you'll need to know how to put it back into the game. First, install UPaint so you can check out how your skin looks on a model before adding it to the game. Also, head
HERE to download the update to UPaint, it makes the process for adding skins a lot better (the old version adds everything to a single UPaint skins package, whereas the updated version creates a seperate package for each new skin you create).
To use UPaint, just open the program, open the model for the skin you've created and import both the head and body skins. Then save the model with a new name - this will be the name your character will have in the game - and then Export character to UT2003 from the file menu. Easy as pie
If you'd like to know what goes into adding a skin and the files you need to create to do it manually, head over to
Loric's Tutorial for info on that.
Hope that helps