Sit with his cage door open in a chair placed in front of the open door. Make no move to touch him. Eventually, I would offer a peanut on a towel, in my lap, and let him come out to grab the nut and run back in his cage. Let your male show you the way. He will guide you, if you let him.
Scarlets are different in that they have very long memories.
If someone hurt them 20 years ago, they will still remember and go to bite anyonne that they think is that person. I always compare the Scarlet personality to the Rottweiler. Both will give back what they get. He will learn, not only that he can trust you, but that you are above him in the pecking order. Once you can hold him, never hold him higher than you heart.