Greg,

I've never replaced mine, but I have removed it and reinstalled it and it is pretty easy. There are strips on both the windshield and the engine compartment side of that piece of rubber that fit in slots which hold it in place. It is designed to be easy to take on and off as you need to partially remove it in order to get to the cabin air filters which are at the base of the wiper. You do not need to remove the wiper.

Unless huge parts of that holding strip are missing, I'd try to clean the track and re-install it before I bought a new one. Mine is missing parts of that strip on the windshield side, but there was still enough there to hold it securely in place once I thoroughly cleaned the track.

I also wouldn't agree that this is only a cosmetic piece. I believe it routes the water off the windshield over the seam between the windshield and the body and into the gutter in the engine compartment, where it can be carried safely to the ground. Among other things, this keeps that water out of the computer/electronics compartment which is located behind the battery. I wouldn't delay in getting this fixed if it were me.

I hope this is helpful to you.

Jim P.