How do I go about removing the trunk tail light wiring harness

We don't have information on the wiring harness. That you would have to order from the dealer. What we have is specific wiring diagrams such as exterior lights, or the wiring for the tailgate lock that is in with the power door locks. I have attached one for an example. The parts department can show you from the parts breakdown the start of the harness.

The junction for the wiring starts at the fuse box at driver kick panel and it goes to the rear via the side panels. It branches out under the front seats, rear cushions etc. To replace the complete harness, you would need to remove the front and rear seats and carpets. Trunk linings have to be removed too.

Is it that bad that you need to replace the harness? If only minor repairs are required, splicing th wires would be an easier job.