Soccer kicking his head off his shoulders Shogun pride style would have been a a good start. Then get the knife away by stomping and kicking his hand. Then get his back or mount and restrain him making sure he dose not try to reach for a hidden weapon. If he did try to get away choke him out. Anyone with a little Mauy Thai and BJJ training could do that.
Fan of: A. Silva, BJ Penn, Shogun, Cain Velasquez, George Soti, Jose Aldo, JDS, Demian Maia