Usually the trainers say to make a high pitched yelp sound like his siblings would do when bit too hard, then ignore him. He may bark and try really hard to get your attention, but don't give in until he calms down. You would have to do this even when he accidentally bites you, whenver his teeth touch your skin. It worked for me. The other, more physical way, is to hold his muzzle and pull on the skin on the back of his neck and say no bite, wait untill he sighs, which indicates rendering his will, and let go.
Remember consistancey is the only way a dog learns. They know cause and effect they do not rationilze.
Goodluck!
