for the record,he is referring to a dremal tool you know the hand held high speed cutting tool. And secondly i would also recommend sending it out...it take alot of special know how to do it correctly and not actually LOOSE power..there is so much that comes into play that it is unreal.A pro would take you head/cylinder and cut,and shape them to there time proven and reliable specs. This is not a practice to take lightly as a LOT can go wrong.
I am sure that Flotec,wildcard,or kennedy,or possibley even chutzell could shed more light on why NOT to jack with it yourself.