Replacing tail lightbulbs

How do you do replace tail lightbulbs? Do you take off the exterior tail light lenses, or do you go through the interior? If you remove the lens, how is this done? I see only one screw at the top (in the area that the trunklid would cover when closed).

The specific one I want to remove is the left rear that's actually on the side of the car.

there are 3 screws, the one that you mentioned and two beneath the corner lense that's on the side of the car. that small section just pops into place and thats all you should have to remove to replace that bulb.