I haven't got to try this yet but have been noting suggestions since several people have commented about struggling with this task. For starters, make sure the factory pinched areas are opened up. You should find a few of these on each side. Take a small piece of the strip and see if it will glide throughout the entire channel. If not open those areas a little. I used a old screwdriver with the tip bend over at 90 degrees to open the factory pinched areas. Lube the rubber with soapy water or some other lubricant. Don't use silicon if you plan to paint anytime soon. Some people apparently have been able to start at an open spot and feed the rubber both directions. Others have resorted to poking it into the channel with a blunt tool. I am still a ways off from installing the rubber myself. Good luck and let us know how it went.

Chuck