I just replaced driver side corner tail light bulb. Open the lift gate, you will see two round black platic fasteners around a 1/2" diameter, they are flush. I used two small screw drivers 1/4" width to pop out the center push pin. The pin will come to a stop or it can come all the way out. Once pin is out, use screw driver to pop the rest of the fastener completely out. Do the same for other push pin fastener. Once both fasteners are out, pull tail light straight out towards you, it may be a little snug. Their are two pins held in grommets. Once out, turn connector counter clockwise, it is very snug. Pull 3157k bulb straight out. Light bulb replacement should take 5 to 10 minutes.
Note: when using screw driver to pop out pins, be gentle not to scratch any of the housing. You can use a plastic with a flat edge.