Has anyone removed their rear OEM rear spoiler, or know what is involved to do so? Am I correct in assuming that it is somehow bolted to the trunk lid?

no they use double sided tape.

DEFINATELY bolted. Just put mine on, and required heavy and precise drilling.

I took my 06 rear spoiler off, it took me 2 hrs and a lot of patience!! Be careful not to damage the paint or wing. It was held in place by 4 screws and a few plastic clips.

Good luck!!

And then you would need to get the holes welded up, smoothed out, and repainted. A competent body shop should be able to do it for a fee. Or if you have a buddy that's a painter, have him do it as a side job.