I've had a look in my Citroen Service guide (purchased it on DVD for £14.50) and it looks quite easy to replace the door glass.
You need to remove the interior door card to get access to a plastic peg which links the door glass to the drive mechanism. The glass has one hole in the bottom edge in the middle where it sits on the up/down carriage mechanism. The glass is attached to the up/down mech by this single plastic plug. But to get to the plug you haveto remove all the interior door trim which is quite easy. I had to do it when I first got my C5 because the driver's side rear window wouldn't work. The peg was missing and broken glass was inside the door. There must have been a break in and the repair shop replaced the glass but not the peg. I got a new peg from Citroen for a few quid.
Once the door interior is removed, you need to take off some trim around the window frame and then remove the glass guide inside the door. This comes off by undoing 2 screws, one from the edge of the door with the door lock on it and one from the internal face near the top of the door.
The Service guide says that once the peg is out, the glass just lifts out from the outside of the door. Replacement is the reverse.
Cheers, Kev
02 plate C5 2.2 Hdi Exclusive SE (now 170k miles 03/21).
Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.
A Ha.... When you say rear window... you actually mean ..rear window. LOL
Anyway, I've had another look in my Service manual for the tailgate rear window (hang on... hatchback or estate ?). anyway, the hatchback window glass has to be cut out and glued back in. So, not really a DIY job.
For an estate it's quite easy to change the glass.
As they say.... If in doubt.. read the question. Sorry about that.
ps. I can email the file to you if that helps. It would come as an XPS Document file which can be opened in Internet Explorer.
Cheers, Kev
02 plate C5 2.2 Hdi Exclusive SE (now 170k miles 03/21).
Used to have:- Xantia 1.9 TurboD SX. 1996 Blue & 1998 Silver Activa. + 1992 BX TZD Turbo.
Check out this company on Ebay (silverlakegaragesouth), they have a late C5 estate in and i was quoted £75 for the rear window complete.
That was about 4 days ago.
Hope this helps.