Broke the XM radio/OnStar antenna cover...Yes, I'm an idiot!

Yeah so I was clearing the snow off the top of my 2008 Sierra when, POP! I broke the cover for the XM radio/OnStar antenna in half. Needless to say I was seeing red for about 15 minutes...

The dealer wants about $400 to fix it ($240 for the part and about $150 labor). Honestly, I'd almost consider it but I'm worried about the quality of the work.

That being said, in doing some searching, I found the part, OEM on ebay for $70, shipped. I'd be crazy to buy the one from the dealer. Even the one on GM parts direct is $100 less. My only concern now is doing the job myself.

Has anyone had their headliner down at all. It looks like I should be able to just drop the front of it. I have a sunroof which may even help matters as I'd have another angle from which to get at it.

Thoughts?

Thanks,

Ray