Pop the top off, removed drum cleaned up the gasket faces and reassembled. The toughest part of the job was cleaning the burned on rear seal material. I am old fart with cancer but 30 odd years ago I fix things for a living. Not appliances but I was a repair plumber, so I have some skills. The gas co use to tell everyone to call a plumber for anything that had gas hooked to it. It was only hard because I can"t work for more than about a hour, then take a 2 to 4 hour break.