Quoted from HowardR:This is a little different. On Gottlieb the glass slides out the front. On at least some Ballys the glass tilts up with the side rails.
Yes, and there are two prop rods recessed into the top edge of the cabinet sides to support the glass and frame. Unless you have three hands, you have to do them one at a time while supporting the glass and frame with one hand. Probably better to remove the entire glass and siderail/lockdown bar assembly, and put it aside. It is removable.