I was not sure if I had posted this yet.
I had heard of this trick and just tried it out.
Instead of using scissors to cut out you new body, Just use a sharp exacto knife to score the outline and then peel the piece off at the seam. The piece will separate cleanly along the scored line. I did the whole body like this and the scrap lexan saparated perfectly in two whole pieces. You do not need to cut too deep into the plastic, just a nice sharp, firm scoring line is all it takes. You will not believe how easy and clean your new body will come out.