Checkout my site, on the links page, theres a few very good skinning links
in there.
For UT Mapping Reference's, Tutorials, Utilities, Patches and some of the
best Links for mappers, visit my site : www.planetunreal.com/fordy
Regards
Fordy
It's a lot more complicated than that. You basically have to edit a
skin, replacing the face texture (or the relevant parts of it) to fit
in your custom pic.