Remove seat, remove side panels, remove solo cowl or passenger seat, undo 4 bolts holding rear cowl to undertail and subframe, push forward to release holding tabs from undertail, lift up and unplug the tail light from harness, undo 2 bolts holding tail light in, remove tail light and start reversing process with new light. Here's the fun part. You need to figure out which is the left signal wires and the right signal wires on the integrated and you you need to splice these into the left/right bike wires. After you've figured that out and connected everything, put it all back together.
