third brake light

I have a question for all of you car smart people. I wanted to get one of those third brake light covers. you know, the vinyl strips that you can put over your third brake light so that when you brake, it lights up in some words? My question is.. how do you get the cover off of the roof of the car.. I tried pulling it, but then decided not to because I didn't want to break it. Any suggestions would be much appreciated. Thanks.

Autozone 15$ manual for your car. OR it might help if we knew what year, or model car. But usually there are clips or a hiden screw or two attaching the peace to the headliner.

it's only held on by clips, carefully pull it down around the edges. until it comes off.

Doing a search through the forum, I found the same question and figured out how to do it.. thanks