Finished glassing my canopy yesterday and had the usual hard time getting the canopy open. Then my wife actually helped with idea of using one of those plastic room keys you get from a hotel. So I took one and sanded down an edge to make it "sharp", and ran it around the perimeter under the glass. It's a fairly soft plastic that won't scratch the canopy but just firm enough to put under the new glass. One swipe and the canopy came right open.