Excellent topic! And I have no idea.

Every response to the topic of "recovery" so far has offered therapy and a good support system as the best approach to recovering from abuse, and I think this would also apply to learning to forgive an abusive parent. In particular, I think it's important that you talk with people who have been through the same and have learned how to cope with their pasts, to learn from them or even just to know you're not alone.

By "forgive," I don't mean that one should excuse the abuser's behavior, but let go of negative emotions toward them. Forgiveness is for your benefit, so that you begin to heal. Therapy is quite helpful in this area because it helps you understand how your past affected you, among other things.