I agree that you pretty much just have to handle them, but instead of just taking a bite, put a pair of gloves on.
I had a couple of BPs that were super defensive when I got them, my enchi male still hates, but I can at least handle them now.
Also fun fact, you are just as likely to get bit while holding a snake if it's defensive like that. 90% of the connecting bites I've received happened while I holding them. It's harder to dodge when they bite the hand that's holding them.![]()