Exhaust studs with headers?

Well... I tried heating them up. The first came out, but it was tough. The second one snapped below the head surface. I tried welding a washer and nut to it but that snapped as I tried it back it out. It's on #7 cyl, so it's a little easier to get to than some of the others. I'm going to try welding a nut to it a couple more times. If that doesn't work, I'm praying I can get a drill bit and tap in there. If I end up having to pull the head, some RHS's are going in it's place.

Any other good ideas for pulling out a broken stud in a tight spot???