Catherine, In the past 14 years I have come to know the damage, first hand, that an abusive parent can do to a four-year old child. She was a friend (40 years of age) and we became too close for me to see the source of her dysfunction, addictions and OCD. We tried over a period of 10 years to live as-is, without addressing the original harm which caused our problems; those driven by her alcoholism, infidelity and pathological lying...the short list. We had a working(as in shared business), living relationship and she was very adept and practiced at the roles she slipped in and out of based on immediate need. We separated for a time, I left the country, when I returned I was told of her "insane behavior" and excesses; people were surprised to find her to be so "bizarre"-the moderating influence of having to construct a semi-sane front, for me, was absent and over the edge she went.
To the topic and finish. Acting to protect her niece and nephew, I initiated a revelation to her sister-for purposes of defending, preventing, harm by her parent to the new potential victims.(he was in a caretaker/babysitter position at the time). Over numerous phone-calls and emails he was confronted by all concerned. His response: "Could be, I don't remember". He was directed into counseling and I have heard from the sister- parent of the two young ones- that she is sure they will be safe; she has been in therapy ever since. (We don't know the mental cost or damage to her).
The woman, my friend, is not my spouse, and is not marriageable-in my estimation. We continue to interact-though not sexually. Her sobriety has lasted 3 years and was necessary before she could confront the perpetrator in any fashion. Sober, cold, critical thinking is the first step. Then concrete action against-Yes, against- the perpetrator. The turning of a cheek takes a very detached individual and is probably not the best response.
My reason for writing is purposeful, for my own healing and forgiveness of what I experienced and was damaged by, over the past 14 years. The injuries run deep in all these types of situations; I believe, in an attempt to moderate the pain, it is spread far and wide.

I don't think that forgiveness is the vehicle through which we become able to move on.  I encountered pain as a child that shaped me (to my detriment, mostly) into the adult I have become.  The things that happened were mostly at the hands of childhood bullies and well-meaning but misguided adults.  There is nothing, really, for me to forgive; the children who bullied me didn't know any better and the adults never would have acted as they did if they knew the harm they were doing.  In fact, one of the things that I have had to overcome is the fact that there really isn't a bad guy I can blame for everything.

Acceptance, on the other hand, might give more insight.  Acceptance that what happened in the past can't be undone.  Acceptance that I am where I am in my life, for better or for worse, and that if I want to have a chance at a good life I have to pick up what I have, where I am, and go from here; wishing it were otherwise won't do anything but waste time.  Acceptance that if I do want to move on with my life, the responsibility is on me to make it happen.  In fact, the biggest act of forgiveness I have had to accomplish was to forgive myself - I had blamed myself for being weak, for being affected by the trauma of my childhood.  I was a child; I didn't have a choice; I coped the best I could.

In my case, the way I did it was through intense therapy.  (Actually, a specific type of therapy called Eye Movement Desensitization and Reprocessing (EMDR) therapy, but I'm not sure you wanted THAT specific of an answer. :)  )  I have spent lots of time (with a therapist) going over the events that caused me so much harm, not so that I could find a way to forgive my tormentors, but so that I could understand how the torment affected the way I experience and react to the world, and thus learn to change my thought patterns.  That is how I am "moving on".  It's not something I could will myself to do; it was something I had to teach my mind to do. 

I guess my thought is that the best way to move on is to stop focusing on the people who hurt you (even if it is for the noble purpose of forgiving them) and focus on how you can help yourself.

I believe "regression therapy" can help some people in cases as these, but not everyone.  The process, as I understand it, is to take a patient back (under hypnosis) to an incident back in their childhood, so they are in a heightened state of awareness, as if it were happening at that moment.  "Retaliation" is allowed when the patient is reassured that they are now safe, and they are given the opportunity to say to their tormentor what they always wanted to say but couldn't.  Then, the "adult" version of them is allowed to enter the scene and talk to the child, so the "child" receives comfort from themselves as an adult (yeah, it sounds weird!) while the adult's perception of it all is passed on to the "child".  At the same time, the child as an adult is able to use the fullest of child memories to see what happened in an adult context.  That can sometimes be revealing because, as children we may perceive someone being cruel or unfair to us, but an adults eye may be able to see why it happened.  For example, an adult may harbour resentment about a teacher for how they treated them unfairly, basing their emotions on how they perceived the events as a child; but "revisiting" the event, or events, as an adult, may allow them to see what occurred from the teacher's perspective, to understand the other side of the story, and that realisation is then brought back into the consciousness and understanding of "today".  The result can be to lessen, sometimes even remove, the memory as something painful.  Personally, I found this helpful in dealing with memories that held back my self-esteem, of strict teacher and of a school room bully.  It didn't however, remove my auto-reflex anxiety of classrooms with very small chairs for little children!  I had to get over that by working in one such classroom and building up a large stock of good memories in that kind of environment.