What retraining is NOT about
I was initially very confused as to what retraining was all about.
I thought it was all about coming up with set of exercises to ease the excessive tension, but I was wrong.
I later figured out that focal dystonia is a state where the body is craving for sensory information to be able to carry out the movements smoothly. The more sensory input I retained, the lesser dystonic reaction I had. I realised that I could input sensory information by making conscious effort to 'feel things' at moments when I didn't have reactions.
Good place to start if you're looking into retraining yourself, is to activate the most outer part of your body, the skin, by trying to feel the point of contact with a foreign object (your instrument).