[mikepellegrini]

As it turns out, that is the only way to do it.

Getting the spoiler off was easy - I drilled the screws out. 5 minutes.

Underneath, it was super icky and at the point it was leaking most (near the drivers side lock) the adhesive for the glass had separated from the frame - there was a pretty good crack - has to be where the leak was coming from.

I cleaned up the trim piece and re-painted it (took it down to bare metal in places). Tomorrow I'll seal it with silicone and put the new gasket on. It'll be like new.