This is a little late to chime in, never the less: that vertical piece snaps on the sliding window, and is intended to keep the sliding window locked in. I learned that one has to remove it to get the window out. So, it just snaps on and off. Drive it off with a wooden block and a hammer.
So, then you have two options.
1. Pull the vertical bar off the window, so you can get at the fuzzy stuff, and glue it in.
2. Order a new one from Sea Glaze. Or, if the boat is under warranty, let the dealer order a new one.
To get the window out you have to pry the horizontal black plastic filler out of the top aft of the window. (freebie.)
Boris