Yes, you will need to remove the back cover from inside the tailgate. You will see near the bottom corners on the side, some small cutouts big enough to fit a screwdriver in. However, using a screwdriver will scratch the paint. Use a panel pulling tool (nylon pry tool) so you don't scratch.
You will need to just pull on the panel until it comes off. It will take some force, but it will come. From there it is self explanatory. When finished just pop the cover back on (make sure you line up the white plastic stickies properly).