as in when you took the pulg out and the threads where ripped off? That is because someone did not use antiseize on them (a must only $2 at autozone) If it is what i think it is, the only way to get the head back to normal, your going to have to use a tap and die to re cut the thread groves?
IF it is just what happened to me, the rubber boot that was on the sparkplug, ripped off and then got stuck on the spark plug, Having a d16z6, the spark plugs where nice and deep so i ended up using a sharp coat hanger to cut a hole in it and fish it out.