[v8volvo]

Welcome!

Yes the #6 glow plug can be a challenge but is certainly doable. Magnets help for avoiding losing the nut (and washer if it has one). A ratcheting 8mm wrench is useful if it still has the original style pinch nut that resists your bare fingers. Many of us use the glow plug electrical bus bar to "fish" the plug out of and back into the hole.

It's easier access when the rear timing belt and its cover are removed, so too bad you didn't happen to attempt it during the timing belt replacement process. But reaching in from behind through the belt is still doable on a 7 or 9 series and can be the easiest way.

Good luck and glad you are with us! As you have noted, this forum is full of good resources from past discussions -- but if you are looking for the answer to a question that you are not finding easily, of course don't hesitate to make a new post and ask.