Stripped spark plug hole

[Red94YJ]

Hi have a 4.6L 2002 Mountaineer and yesterday a spark plug blew out of the engine. The threads looked good so I thought I would try to reinstall the plug.

I gently tightened it and found that the few remaining threads stripped out right away.

I have been reading about this problem on the forum but I have a few direct questions.

Does the engine need to come out to remove the head?

Does the head need to come off to use a heli coil kit? Is that a good idea?

Any other tips?

Thanks

Adam