I routinely install fuel tubing on my pull starts. So far, the only kind that gets torn up are the smaller tubing sizes. I use medium or larger and have great success. The only caution to use here is by adding fuel tubing, you actually decrease the length of your pull.
The length of pull that should be used is 6-9 inches. When you add the tubing, you reduce that by whatever length tubing you install.
Number one cause of busted pull starts is over pulling the pull start.
Something that can help the fuel tubing is to install small washers on either end of the tubing. Keeps the handle from digging into the tubing.
As for the easiest method for doing this mod, a good pair of vice grips is a must. Pull out the line about 6-9 inches. Apply the vice grips to the line near the pull start casing. This is to prevent the line from retracting into the pull start. From there, just undo the line in the handle, put on the first washer, tubing, second washer and then re-apply the handle. Piece of cake.