Are you saying you snapped the studs? That can be fixed, easier if there's a stub you can work with, but it's fixable. If you just pulled the studs out and stripped the mount it's time to investigate Helicoil or Timesert thread repair.
Chunks of the cylinder are a different story and will probably require engine disassembly to repair, either by replacing the jugs or by welding up a filler pad and reboring/threading a new mount.
