Foam seal peeling off from side window glass

tkl

We bought 2013 T@B used and it’s in great condition thanks to the previous owner. 

The only issue we have right now is that the foam seal is peeling off from the glass. We can carefully hold it up and shut and lock the window so no leaks currently. Some adhesive is on the glass. We figure we should clean the dried up adhesive and glue it back. Otherwise, we are afraid the whole thing will come off sooner or later. Can anyone help us by suggesting steps and what glue and cleaning supplies we should use? Do you suggest we replace the whole foam seal? It looks still in good shape. The other side window is still intact.

If anyone has some idea if the original foam seal was self-adhesive type or not, also helpful for our knowledge. 

Thank you the community so much in advance!!