I just did this myself, and broke a couple of plastic tabs - !@#$%^&*(

First - The cover - as you face it, on the bottom of the plastic, there are 4 clips which hold it in place... one on each side right adjacent to where it touches the glass, and one on each at the furthest bulge point away from the glass.

The furthest away simply snap straight in and out.

The ones close to the glass are a little more tricky, as they are slot / slide clips. As mentioned, try and "pinch" or push in on each side close to the glass at the bottom while gently pressuring back to get the cover off.

Once opened, I made the mistake of pulling the entire assembly off the glass, and disconnecting the wiring (more plastic tags broken) before finding / realizing that there is a metal cover piece which needs to be removed to access the bulb - whether or not the assembly is affixed to the glass.

Right way to do it would have been to leave the wiring and assembly in tact and attached to glass... simply pinch and remove (takes some pressure) the metal cover from the plastic assembly to access the bulb.

Good Luck.

you should be able to push the two tabs on the side in and pull the cover toward you. Mine was a little sticky at first but did come off. If you are having erratic brake light problems, you will need to pull the assembly off and clean the contacts on the underside of it. To do that you pull that assembly straight toward you also (If i remember correctly).