There is a special easy out for this. If it cant be used or the remains of the plug still wont come out then the head will have to be removed and the spark plug removed from the inside.
A machinist may be better suited to do this if you end up having to take your engine apart.
Usually when the cylinder head gasket is blown (broken or damaged). It cannot be repaired but has to be replaced with a new head gasket.
Cannot be broken
An element is the only substance that cannot be broken down.
The atom cannot be broken by chemical methods.
No, you cannot.
No, it cannot.
All of the elements of the Periodic Table cannot be broken down into simpler substances.
Atoms cannot be broken down into simpler substances
an element is a substance that cannot be broken down into a simpler form by chemical means
molecule
An element cannot be broken down into a simpler substance by chemical means.
Broken liver cannot be cured without conducting an operation.