[Richard]

Ok, the generic name for the felt is Fin Seal. Several places on the net carry it. It comes in different widths and heights. I don't remember exactly what size the windows take, but I do know the sliding tracking and the crosspiece bar have different heights. I got my fin seal from Peninsula.

First step is buy a set of picks. Lowes has them, so does HF. Don't start without them. You will use the curved hook a LOT.

Start by looking at the bottom track the window rides on. Use the hook and pull that out. Now pull out the top one. You should be able to take the sliding window out of the track now.

Go as far to the end of the felt as you can get and slice it with an Exacto knife. Use the hook to pull it out of the T track its mounted in. Ok the easy part is over.

Spray some silicone in the track and slide the new felt in. You just keep slipping in the track and sliding till you fill up the track. Repeat for the other tracks.

This will all make sense once you start taking the window apart. The first one takes 3 hours, the second one an hour, and the rest 30 minutes. It's a steep learning curve.