A Technique Called the Grid...
A lot of people have bad memories. Richard Bandler once said that the best thing about the past is that it's over. For some of us, though, it seems to be where we live. One technique developed for taking the sting out of bad memories is the V-K dissociation. A hypnotherapist named Dan Jones has a version for memories with any strong emotional component, which includes scrambling the memory. This technique works in a similar, but elegant and precise way. I learned it from The Coaching Masters, in their NLP Master program. It's called the grid.
You start with a simple grid of four squares. At each corner, you'll place a component of the memory, wherever it feels right to you: time, place, things, people, and feelings. One by one, ideally, you take the parts out of your memory and put them in the corners of the grid. You then notice how you can observe each part, by itself, and still be okay. But, what about really stubborn memories?
That's where phase two comes in. Take the feelings from the first grid, and make a second grid. This time, you'll pull it apart in the following way, still putting the components where they seem to fit best: what it looks like, what it sounds like, what it smells like, what it tastes like, and what it feels like. This adds a layer of dissociation, and provides a safe metaphor for the emotions. Then, consider the emotion, and realize that the emotions are not as strong.
Of course, as with every technique, this requires consideration of ecology and dealing with any secondary gains first, scaling the experience between 1-10 (or any number, depending on how the feeling changes), and future pacing in case the memory comes up again. Keep in mind that you must keep the components separated as you remember the memory in the future. Memories are organized both sequentially, and contextually. You are, in a sense, breaking up the memory in context, so you can still remember it accurately, without the emotion getting in the way of the learning.