Have you tried clicker training with him? Targeting to the side of the cage for a treat? You could start with that simple behavior (the treat can be delivered through the bars). Then, when he has learned that the click means treat, you can click him for lifting his foot. Or if he keeps lifting the foot, start with that - give him a seed or piece of nut (whatever he prefers) every time you see him doing it. I would definitely work on a really positive training relationship with him before you get him out of the cage. Every time you get him out and it is a battle it just reinforces the old patterns of behavior. Start some brand new patterns that are safe for you and safe for him! It is great fun to train and Amazons love the attention.