I use both Hi Tech and Ameritool flat lap machines. When my discs wear out I remove the top plates from the backer plates and put on new top plates with PSA adhesive. It's difficult to remove the top plates and I have to use flat head screw drivers to pry the old discs off of the backer plates. Is there a better way to remove the old top plates? Is there a type of solvent that would dissolve the adhesive without destroying the backer plates?

A heat gun will help soften the adhesive. Laquer thinner, used sparingly (so it doesn't affect the underlying acrylic, it could craze or possibly crack if used in too high of concentration), followed by Isopropyl alcohol should take care of it.
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