[Randy in ca]

There are 2 screws on each side, above the pivot studs, that hold the top bar to the rest of the frame. After they're removed the top bar should lift up and out easily barring corrosion, etc.. The glass should then also slide up and out of the frame. Don't believe that the pivot studs need to be removed unless the threads are longer than they should be for some reason and are binding against the edge of the glass.