no you can not do this.
our cars do not have a roof skin. Say for example the BMW E46 M3, it has a roof skin that is seperate from the rest of the car and is tack welded + sealed onto the car. You can simply drill them out and peel it off, then replace.
The 6gc however is not like this. the roof is fully attached to the body. If you were to remove your paint you would see where on the A & C pillars the roof is seam welded with the rest of the body.
Actually i have a picture, if you look in the bottom left of the picture you can see a coppered color line running horizontal across the C pillar. Also note there are no tack welds along the roof line.

aftermarket sunroofs are common and should be done by an authorized service station.
This post has been edited by playr158: Jul 14, 2008 - 12:56 PM