the glass is held in the window regulator at two points. there are two 1-1.5" u-shaped pieces that the glass is glued into. remove the interior trim panel, speaker and plastic weather shield, you then need to get the glass loose from the regulator. there are openings in the inner door structure, but it may be difficult to get the glass in a place where you can get at the places where it's glued. if you have to, unbolt the regulator (or even cut it) to get the glass where you can work on it. then you should be able to push the glass up to the closed position. with the glass disconnected from the regulator, you can unbolt it from the door and remove it through the larger hole. new regulators are available at auto parts stores or RockAuto (usually Dorman brand) they usually come with a new motor and run around $75 at RockAuto.
to reattach the glass, clean the old glue off the glass with a razor blade and clean it (and the regulator attachment points) with something like parts/brake cleaner. i use 3M yellow weather stripping adhesive to re-glue the glass into the attachment points. after gluing, close window and do not operate it for 24 hours.
here's a video that should prove helpful:
https://www.youtube.com/watch?v=z8UfSotzIiA
tips:
1. the bottom of the rear window channel is held in place by a single bolt and a spring clip. remove the bolt, pull down on it and comes out to give you more room to work.
2. when done, spray silicon generously down the window channels for smooth operation. do this to all your windows once or twice a year to avoid problems.
3. sometimes you'll find the glass has come out of one (or both) of its channels. if you rotate the glass down at the front you can work it back in.
4. if the glass will not stay up once it's detached from the regulator (it usually will), you can hold it up with a couple of pieces of duct tape, or use a rubber door stop as a wedge between the glass and the door structure.
5 use masking tape in a few spots to hold the weather shield to the door while you re-install the interior trim panel.