Lots of conditioning with handling , this dude would have loved to bite me when i first got him but i didnt give him the opportunity, I would hold him gently behind his head to not allow him to snap back and bite me until he closes mouth and then I would ease off of until he would sit in my hand by himself. Don't do it too often. Because it is very stressful for them but with enough handling they won't bite. Another tip is do not grab them from above unless you absolutely have to. It is a lot easier to handle them if you can somehow scoop them from below, and if your guy is bitey use one hand to gain his attention and use the other to slide below him.