HiCustomerand welcome to JustAnswer,
Are you replacing the bulb in the tail gate or the outer light?
Thanks for the update.
The tail gate panel will need to unclipped. To do so, remove the square plastic cover where the pulldown strap is. It'll just unclip with a little prying. Behind this cover, remove the 10mm bolt along with the strap.
Next, using a hard plastic knife or similar, pop the tail gate panel out of the way. No need to totally remove the panel. Just enough to access the bulb you need to replace. If you don't have a hard plastic knife or similar, you can always use a flat bladed screwdriver, but be careful not to scratch the body.
Hope this helps. Goodluck.
Did you get the bulb out ok?
When you get the panel out of the way, twist the light bulb socket counterclockwise.