Exhaust stud removal/replacement?

I have no pictures at the moment, but this is pretty self-explanatory. My exhaust studs are pretty bungled up. Two have broken at the engine, and the other six are slightly bent, so as to fit through the aftermarket exhaust flanges. This is as it was when I purchased the bike.

I'd like to rectify this. That means removing and replacing all the studs. Buying the replacement studs is easy enough, but how do I remove the existing bolts? The broken two I may just take to a machine shop, but what about the remaining six? I have standard tools, but no welding or other specialty equipment. Or, alternatively, what am I looking at as far as shop labor to remove everything?

Thanks a lot.

 

On the ones with some stud still showing, have a nut welded on, the heat of the welding also helps with the removal, a good welder can also weld a nut onto the ones broken off flush, keep away from easy outs, you could wind up in deep dodo....

 

I'll echo Wizard's sentiment. I'd just throw my machinist/welder buddy some cash and let him worry about how to get it out. Much easier and less worry than taking it on myself.
In practical application, I've been successful at removing studs with the double nut method, but only so long as the stud was intact.
Best of luck Wolfy.

 

Thanks guys. I think I'll throw money at this one and leave it to the professionals.

 

Or dissolve them yourself: http://www.chemical-supermarket.com/pro ... ductid=574