Its really easy, don't have to do any "wiring" per say. Don't use the butt connectors that come with the kit. Go to advanced auto and buy 16-14 Gauge 5/32 Bullet Connectors. Like $3 for a 20 pack. Those connectors will connect with the stock harness. So connect one male connector to each wire on the Yoshi kit and connect to the correct stock female connection and wala...all done. Easy stuff. Although I have the motodynamic tail lights so that is just to hook up the light for the license plate.
here is Yoshi kit on mine