just did a mylar removal on my Royal Flush, and used a hairdryer, with eucaluptus oil. The glue was very easy remove whilst still warm, if I let it cool then it was a little stubborn. I lost no paint, and the mylar covered 2/3's of the PF. Never knew about white spirits, will have to grab some from bunnings to try (not to drink lol).

One for the playfield two for you never hurts. Makes mylar removal more pleasurable