So this one is pretty easy if you have the right tools. I helped some one change their Back up light on the 2006 Saturn VUE. IT would be the same process if you needed to change any of the lights in the light box.
A note about the Allen wrench and light:
I had a cheap variety bag that i bought from Lowes if i had to guess it was English but it wasn't marked so i'm really not sure. so if you have something like this already you probably don't have to purchase a new tool.
When you go to purchase your replacement light i would consult either the clerk at the auto parts store or your user manual to see which is the best replacement bulb for this vehicle.
Step 1: Step 1: Open the Tailgate
Open the tailgate of the vehicle to reveal the screws. The screws are located on the side of the light box. They are around the sealing area of the tailgate. You should be able to see the easily.
Unscrew the two screws using an allen wrench. Unfortunately my Allen wrench did not have its size indicated on it but i have included a picture of it so you can get a general idea of the size.
You may wish to place the screws somewhere that is relatively safe. There is a nifty indented area in the rear of the vehicle that worked perfectly for this.
Step 2: Step 3: Gently Remove Light
Once the screws are removed the next step is to simple remove the light box. Sometimes these things feel like they are stuck. If you gently/barely rock them side to side some times you will feel them start to be unstuck. The light box should pull just about straight back. It is not held in place by any other screws. There are two guide posts on the other side of the light that help keep it in place on the side with out screws. These just slide out of thier slots in the body of the car.
Once you pull this off you will see the wires for the lights.
Step 3: Step 4: Replace the Lights
To change an individual light you will have to remove the light socket from the light box. This is done by twisting the socket. The are not screwed into the light box but they are twisted into it. Its like a twist lock kind of thing.
Once you twist it you will feel the socket become loose and you simple pull it from the light box.
When it comes to replacing the lights i had an extra light hanging out. I i do not know if its the right kind for this application but it look very similar to the light i pulled out so i used. Do your self a favor and ask the clerk at the auto-parts store which light you should get.
The lights just pull out of the socket.
Replace the light and then reassemble everything. Voila.