Teaching your dog not to Bite
Take him by the jowl on the top pinch to the bottom and shut the mouth. Say "no, no, no, no bite" repeat it 2x. End with a tap on the nose...nothing is to be done in a loud voice...just keep it easy yet stern. If you just keep it a teaching moment they will learn.
Praise afterwards
After the no bite process...hand your dog the toy of preference to chew on. Just state matter of fact "here's your toy" then play a bit to avert attention to the toy. He will catch on if you stay consistent and cool headed. If you teach him to sit you can just avert attention to a command then hand him the toy after the no bite command is used.