Braided cotton (from any hardware store) works well. get something
that feels strong and soak it AND the window rubber with plenty of
lubricant.  I use Wurth Rubber Care,
http://www.amazon.com/Wurth-Rubber-Care/dp/B0002XRB0M but a good mix
of soapy water will work also.

If you are doing the rear side windows, start in the upper rear
corner of each side, especially if you have the late model air vents.
This way it's possible even with Westy cabinets installed.

>What kind of rope or string do you use to put around the seal when putting
>windows back in?
>
>Chris