I'm allergic to my woolly mammoth when he sheds, so I just got an Oster razor and blade (ask your tack shop which one would be course enough). Make sure he's CLEAN - all that fine dust will dull your blades out. It did mine and I had to leave him half clipped until the next day. I avoided the face and legs, but I don't think it'd be a huge issue if you're careful. I did do his fetlock, though. That was easy.
It will change his color appearance since the skin will show through and the roots are often different colors, but it should be the same as his summer coat once it grows out (a week or two)