yikes... for my safety.. I'd prefer to take away the mullions.. bits that hold the glass in place.. and remove the glass intact.. I believe if you broke it out .. you'd have bits still stuck around the edges.. waiting to grab you .. all the years it would sit there as a trellis.. they are made to be removed for glass replacment.. or in this case just removal
there's always a chance to attack it with a hammer if you have trouble removing it..
