Thread: Removing broken manifold crossover pipe studs

'99 - 3800 engine

I need to remove the broken studs at the rear of the manifold crossover pipe (where it connects to the exhaust).

See pic.

I believe these are studs with double nuts and they do not thread into the lower flange. Can anyone confirm? I know the nuts are frozen tight, but can you also confirm that the lower nut is not welded to the lower (exhaust pipe) flange? If this is true, I should be able to just punch these babies through. Just want to be sure before I start banging away.

Thanks