I’d put a couple of dots of weld on it, build it up a little. Then tack a washer (on the inside hole of the washer) to the weld build up. Then weld a nut to the washer. The heat should loosen it up, then you should be able to turn it out with the nut.
Oh how I would love to do that. And I might give it a try. I don't have a way of running a TIG on the farm, but that would be best.