Well, it took a while for him to let me even so much as touch his ears, but I groomed him, and by groom I shaved him down. He was so horribly matted that it was the only thing I could do, I knew he wouldn't sit still for a brush out so I did the quickest and easiest thing I could think of.
Don't worry, he wears a sweater to keep warm
The first pic is his before (when he first came home)