How do you change a brake light on an Isuzu Axiom '02?

I have removed two screws, but I am unable to remove the brake light cover. Something is holding it, but I am not sure how to detach it.|||they are hidden inside the car. pull the carpet out of the way to get to them.|||screws are holding it they should be in the trunk or an easy to access place|||I would imagine its being held from the inside underneath the carpet material.. if not, check for screws along the trunk lining.