Some chameleons will never be ok with handling and others can become ok with it...it takes patience. Hand feeding can help...moving slowly around him will help...try taking him out on a stick by
Putting the end of the stick right in front of him and letting him walk onto it on his,own and he may walk up your arm. Don't grasp him/put your hand right around him because it may make him react as though you were a predator. Don't pull him off branches to take him out of the cage...let him walk onto you.