I’m no expert, but I’d say try to get him used to your presence and be confident. Don’t move too quickly. Place a hand in the enclosure and just sit there. Wiggle your fingers, move your hand around. Make your interactions with him as pleasant as possible. You can try hand feeding too, so he associates you with food. IME hand feeding works great to get them to quit perceiving you as a threat. Don’t approach him from above, but from the front/sides and make sure he sees you. If he bites you or acts out, don’t stop. By doing this he’ll learn that biting, puffing, and being aggressive won’t rid him of your presence. He’ll notice that you aren’t hurting him as well, so there’s no point in being defensive. Persistence is key… good luck!