The character needs to be exported and imported into the UT editor, at which I believe it can sometimes lose its bone structure entirely, meaning you'd have to redo it. As it stands, it requres extra animations, hitbox information, bones, joints (it wasn't boned properly either) and new animations. Since it wasn't boned properly you'd have to rebone than animate or try animating with the skeleton already there, which would be a pain. Add the fact that by today's standards the model is ridiculously low poly and the textures are a very small size, it'd be better if somebody remade a high poly Jazz from scratch for UT2K3.