You might as well remove the glass, and the bottom channel. You can buy a piece of setting tape at most auto glass installation shops, or have them replace it for you. Not a difficult job, just need to make sure that you put the glass back exactly where it was when installed at the factory. Usually, you will see dirt marks that will help with the placement. I use painters tape and a black marker to mark the boundaries. Once the glass is put back in the channel, you spray the setting tape with WD40 to snug it up. Now, if you haven't already disturbed the original bolts that hold the regulator to the door, spray the bolts with some paint, and allow it to dry. This will mark the original setting of the regulator. When you reinstall everything, this will make it a lot easier to get everything aligned like when it was new. The bottom of the vent window channel has a nut that holds a screw to the door and the channel. You need to remove both the nut first, and then the screw. If you don't remove the screw, you risk scratching your paint as you lift the divider (vent assembly) from the door. Sometimes you have to turn the vent window assembly 90 degrees to lift it out. Depending on your model, there are a number of screws that need to be removed to take it out. It is the first thing that comes out, and the last thing to go back in. Working on door glass is always a pain, until you do a few of them. These are general instructions, and your car might have other steps necessary. Check with the service manual for attachment screw locations, etc..
