I've had good luck removing them with this method. 1st I triple thick the artwork close to the trim to seal it. Lay BG art side down on a soft blanket on carpet. Lay a piece of oak stock like 1" X 1" x 6" flat on the front side if the glass. With a plastic hammer gently but firmly tap the trim while applying light pressure to keep the glass from moving. Work slowly and keep tapping working from one edge and then the other. Once the trim is moved even an 1/8", it will come off easily.

Gatecrasher here sells them. (he makes them and everyone else is reselling his stuff) Early Bally's use a 3/16" trim. Finish the bottom of the glass with triple thick. Pick up some friction tape at Home Depot and and usually two 1" strips applied over each 1/3 of the edge will do. Install gently with a plastic hammer.

I've done over 20 this way without breakage.