Handy tip that. Learn something new every day.
Wish id known that a few years ago getting snapped manifold studs out of boxter/996 engines.
put a washer on it and then weld a bigger nut on, stick the power right up on high..... on the vertical like that metal might drip out, don't worry too much about that, just don't let it drip on you
you're trying to get it as hot as you can (washer is so you don't weld to the casing)
don't let it cool right down, just wait for red glow to fail so it's not soft
might have to do it a couple of times, it's the heat that frees it off more than anything
