I used a pair of scissors to cut the one I installed off my AC/DC Luci. It worked well.
Edit: I assume we're talking about the thin clear plastic sheets that just lay over the playfield and kind of free float to some degree. I lifted an edge, slid the scissors under, and started cutting. Obviously I took care not to scratch or gouge the playfield with the scissors (I didn't let them touch the playfield). You don't wanna get too rambunctious when you're cutting.