So you end up with 1 Centimeter holes in the roof? That kinda sticks. Have you seen this done or done it yourself?There is 3 screws... under a plastic panel. 1 screw on each side and one dead center where the 3rd brake light is. They are 10mm screws.
When those are released, there are 2 clips that hold the whole spoiler on. They are a tad bit tought but a little effort will nudge them.