I used a small extremely sharp pointed pair of scissors to remove non-adhesive mylar on all my games. I cut the mylar ring in four quarters. If your looking at the mylar ring as if it were a clock scale....the cuts are made at 12, 3, 6, and 9 (3 and 9 are at the metal pop rings).

Make sure the scissors cut completely through the mylar ring edges. You can lift the plastic pop bumper lower ring up at each section of the cut to get you through the mylar completely.

Once the cuts are made you can use a heavy duty linemans pliers to pull a part the mylar ring, but you'll need to use some force. Be very careful not to scrap the playfield while pulling off mylar with the pliers. You might be able to slip a thin piece of cardboard under the mylar ring before attempting to pull off with pliers.
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