Try the trade up game: every time you take something away, he gets something even better. Always give back the things you take away, and don't make him wait long, since he's a pup. Here's an example: give him a bone. He starts to chew. You walk over and show him that you have some tasty treats (something extra good - maybe organ meat, hot dogs, or cheese). When he drops the bone, give him a couple of treats while you take it away. Give it back and repeat. You're teaching him that when you take things away from him, it's a good thing.
Also feed by hand and try holding one end of the bone while he chews the other.
Whatever you do, don't punish the growl. Dogs who get punished for growling stop giving that warning and just move straight to the bite.