[Tempest67]

you do not need to remove the vent windows to add new rubbers/seals.

Now that you have the rear channel out you can disconnect the glass from the regulator, and leave the glass resting in the bottom of the door, until you are ready to reassemble.

Also, the vent window rubber can be installed without removal, but you will have to make a cut at the bottom of the rubber, at the pivot pin. Cut the rubber from the INSIDE of the cab to the pin hole (NOT THROUGH- stop at the pivot hole), and you can squeeze the rubber in. You will be left with a seam on the inside, but this will avoid having to remove the vent window.(see pic)

Hope that makes sense, and good luck, as I find my hands and forearms get all cut up when I am working inside doors.