I recently bought a punto 02 off a friend who was gonna scrap due to the head gasket failing. So I bought it off him so I could fix it up and sell on for a profit, I also thought it would be a good learning tool as I know the process but neve put it into practise. The only issue is one exhaust nut. It's the only one left and won't budge. Inevitably it's now rounded off. Would anyone have any suggestions on how to get it off. I don't have access heat or welding equipment so both those ideas as out.