try this ....... I had the same problem once and used a time sert kit to fix the issue .. head did not have to come off .. Make sure you use lots of grease on the tap and I used a small hose and duct taped it to a shop vac to suck out what fell in ..
It's fixable my buddy's 03 get shot his spark plug out of the head a few weeks ago he took it to a shop and they fixed it, it's been running for about 3 months now with no issue
Well it looks like I'm fine...For now, I won't know until I fire it up tomorrow.
I went back to the garage, after I calmed down a bit, and on my dad's advice dumped two cap full's worth of Marvel Mystery Oil (MMO) down the plug hole.
Waited 30 min and the plug came right out.
Upon inspection the threads on the plug look perfect and there wasn't any metal bits on them. I decided to try to put it back in and it screwed right down and stopped and I unscrewed it and it came back out and right down tight again. I guess I overreacted since it felt weird going in the first time.
If you start it up let the engine heat up you might be able to get the plug out. I'd give it a try, but turn it off before you do!!! It's not the worst thing in the world; good luck either way.