first you need :
pictures for textures (all textures 128X128 and .TGA)
or you can create them with Paint.Net (free)
now go to your toribash folder, found custom and search your name (good luck!)
after, put all your items out (those you want to change, the muscles can't be changed) here
ex.: trails, textures, etc.
lets return to your folder...
put your pictures texture in your name folder, name your pictures like that
and you're done!