Behind the rear fender there are two bolts that secure the tri-light to the fender. Remove them, the unit will drop out into your hand. Oh, jack the bike up first and let the wheel hang down, it gives you a little more room to work. Remove the wiring plug from the old light which should be on the fuse box side of the bike, just behind the fuse box. Reach up into the fender in that area and you should feel the connector. Not much room to work. I had my rear wheel off for something else, so it was a piece of cake. Mount the new light to the fender and run the new wiring harness forward to the connector. Secure all the wires so nothing hits them and that's about it. Of course, if you have a '08 or older bike, it may be different.