For that center section if you have a rusted bolt, instead of an extractor take a Chisel or drift (as sharp as possible). Hold at a 45 degree angle to the face of the bolt and hit it with a heavy hammer. It will bite into the bolt face and eventually start turning. This is how I take off the big lock nut on the axle hubs also without buying an $80 socket that I will never use for anything else.
