Answer:
Use a #20 Torx screwdriver to remove two screws located on the inner side tail light assembly w/ trunk open.
Pull taillight assembly straight back from the vehicle to get it off. You may need to utilize a wedge to gently work the top and bottom of assembly away from vehicle on outer side. If so, be careful to use a protective layer (such as a thin piece of cardboard) next to the body to prevent scratching the paint. A wooden kitchen spatula works with out scratching.
Once removed, twist applicable light cover counter clockwise and pull to access lightbulb.
You may want to apply a small amount of lithium grease to the two plastic stud holes before reinstalling the cover to make it easier to remove the next time.
*** For my 2006 Jeep Liberty, the #15 Torx screwdriver worked best. It would also benefit having a magnetic screwdriver since the left tail light area is hard to handle small screws; that is, unless you have tiny hands. :)