I have not read the above thread on installing the window trim, but here is what I did on mine.....
I have a '77 930, the last year with the pop out windows which I really like. I thoroughly lubed the gaskets with McGuires Rubber Treatment- good stuff, but you could also use Armourall- which I hate- or just a soapy solution with Dawn or similar out of a spray bottle. The soap/water will dry however as you use it.
You do have to be super patient- I used some plastic and wooden tools- some I made. Do not use metal tools. Plastic putty knives work well, and I used wooden popsicle sticks and a tongue depressor cut at a straight angle, then sanded to have a clean snag free edge. If you don't have any of these, go to Lowes/HDepot to the paint department, and look around the paint brush area for items you can use. The plastic tools are very inexpensive.
The whole gasket goes in pretty easy- UNTIL you get to the final corner- this is where the patience comes it- you will have to work each end slowly to push it into the grooves- I bought mine from Pelican, and they worked just fine for me.
MAKE SURE you have the right gasket on the correct side! When I took my old ones off, I found they someone had installed the old ones to the wrong side, making the installation problem even worse!......
Of course, you have to have to have the side windows out of the car to do this.....
Tim