Snapped Exhaust studs part II

[maxzer1500]

Don't see why the cheaper would not do the job and you might never use it again. Practice on the other head by all means, also don't mix the collets either and when it's back together a light tap with a plastic faced hammer on the end of the valve tip ensures the collet is properly seated. The piston deposits i would carefully remove without removing any metal and is that carbon on the edge of one of the rings, rings need to not be tight in the groove. Keep everything as clean as possible, i would use clean lint free rag to fill/cover holes and lay something like an old towel over the whole thing, clingfilm sounds a good idea as long as it don't encourage condensation.