HELP, how do I fix this?

Depending how damaged the threads are, did you try running a tap through and see if it is ok after that?

If not OK, a Helicoil would be the best solution. Not sure how you would drill/tap and keep the shavings out of the case though. 

Maybe there is enough access if you pull the #2 cylinder?

This is one bolt hole that Rotax will allow a thread insert like a Helicoil or a really good one is a Timesert.

Within 24 hours of the “panic” I am back flying. Amazon delivered https://www.amazon.com/s?k=time+sert+kit. 

What I did was put 5 psi of shop air fed into the mag plug hole to kept positive pressure while I drilled and tapped the stripped hole for the threaded insert. I used grease on the drill, and tapped with regular cleaning to keep the contamination from falling into the engine. Thanks Roger for the encouragement.