My Iguana isn't very friendly. How to make him more sociable?

My Iguana is not very friendly. He is a year and a half. I just got him. From what I heard his previous owner was very neglectful toward him. Whenever I try to hold him or pick him up he just tries to escape and scratches me to pieces! How do I make him nicer? Is there anyway to train him? Any advice would be great, thanks.