rusted exhaust bolts

[norm]

:-/im having trouble getting the studs out of my engine for the exhaust. that is to say they twisted off!! any suggestions how to get the remainder out ? theres enough i think i could get a pair of vice grips on.any tipps?

[bugguy]

broken stud repair ,,,grind flush with head ,,find center of bolt center punch it ,drill with small drill then bigger ones till your up to 1/4 inch or even one size bigger ,,then re tap with 8mmx 1.25 metric tap ,,go slow and don't break the drills or the tap