The vet will be able to handle it from his end - they deal with animals all the time. If he is used to reptiles, he will know what to do.
Remember that your little guy is scared and not really angry. I would be scared too if some big pink-faced demon stuck his paws right into my home and tried to eat me.
You might try a few things:
1. Lure him onto a removable stick with a treat like his favorite feeder
2. Shoo him onto a removable stick with your other hand
3. Wear neutral colored gloves and use brute force
By "brute force", I mean be firm but very gentle. Don't tug or pull him as you might hurt his toes. If you hold him by the body by wrapping your hand over his back, sliding your fingers under his belly, and gently lifting, the pressure should cause him to let go of the branch and grab your hand one foot at a time. Watch out for the prehensile tail to make sure it comes loose too. The gloves should help with any biting.
My preference is to give my little guy plenty of time and let him make the decision to move onto a stick or into my hand (which may necessitate me standing with my hand out for several minutes while he makes up his mind), but depending on the temperament of your cham, this may not be a workable option.
Have your transport vessel ready to go before you get him out. I use a clean bucket with a few vines in it. Other people have used boxes or small screen cages with success. For me, the bucket is easy because of the wide opening and the handle, plus the slick sides mean that my little escape artist cannot get out. A towel over the top makes it dark and safe.
Your droppings should be fresh and moist (from that morning would be best). Keep them in a plastic baggie in the fridge until you are ready to go.
Best of luck to the both of you! My little guy pouts after a vet visit, so don't be surprised if he hates you for a few days afterward.
The Chamousine:
https://www.chameleonforums.com/att...n-lower-jaw-jacksons-cham-wp_20130624_001.jpg
