This video will demonstrate how to replace a taillight assembly on a 2006 Nissan Xterra. I believe that this procedure will apply to all Xterra models from 2005 to 2015, however I can't verify that.
This video was specifically created to show that the tail light assembly can be installed without replacing the inside wiring. The majority of tail light assembly replacements don't require the inside wiring to be replaced. If you have a situation where the inside wiring does need replacement, there are other RU-vid videos that will show how that's done. It requires a lot of plastic trim removal. Thanks for your comment.