I used a piece of weedeater string and started in the door and pushed the string into the wire bundle and kept pushing until it comes out under the dash/kick panel area. It took about 30-45 minutes to get it through because you have to feed and pull back and feed and pull but eventually it will make it. Once I was through to the dash side, I taped the LED wire to the weedeater string on the door side and fished it back through so the wire comes out near the kick panel. It is time consuming but worth it to me cause I like the look. Inside the door I cut the LED wire and used male connectors on one end of the wire and female on the other so I can unplug the LED wire if I need to remove the door panel. Getting it through the wire passage between the door and car body is the hardest part of the process. There is a lot of space in the rubber boot that the wires run through. Just have patience and keep trying and eventually you will get it. I used .105" weedeater string. I use weedeater string anytime I need to fish wires through the dash or fire wall or anywhere. It is flexible yet solid enough to not bend or damage other wires. I'm sure almost any size would work, my only thought would be if it is to small of a diameter it could bend and get hung up when pushing it through. Good luck and post pics if you get it done.