x-acto with a #11 blade, and replace the blade often. With almost no pressure, you will have a clean cut and not even touch the surface under the release paper.
Back in the days when I did alot of airbrushing, I got pretty good at it. I often used masking tape on t-shirts, and would cut the tape, while on the shirt, in the same way, without damaging the shirt. It does suck when you cut through the tape, but not the glue applied to the tape though
Practice some first if this is a new technique to you. You will need to learn to replace the blade before it starts getting dull. If you can feel it dragging or skipping, you used the blade too long. The weight of the knife is about all the pressure it needs. Also, try to make the entire cut without lifting the blade out of the cut, because getting the blade exactly back into the cut, without touching the underlying surface, is not an easy task.