The key is the right rope, I was trying it with a thinner twine, it dug into the rubber and broke, causing multiple problems, the 1/4" cord as described works great, I had an installer do it once and watched him, he started the rope from the bottom middle. I have done it myself about three times and have never had much trouble getting the plastic in after with some soap lube. Important to center the plastic when you start, it and cut to the right length, especially not too short, can't add it back on.