Just remove the light piece and run your wire up to where the factory wire clip is, and then slice up the wire a bit and join the wires from the led to the connector on the bike. I had to make a hole on teh oval factory light holder to put thewire through.
Thanks for the reply mksliao. Do you have any pics of your FE setup? I have not started this project yet. I want to take my time with it if I end up going the DIY route, I am off next week so I may begin it then.btw did u buy the light yet, cos i bought 2 i was gonna use a pair on my car, tooo much work to do it.