How hard is it to take out and install the rear quarter window? My drivers side is cracked, I brought the glass, but im not shore if I should do it or should I take it to a shop? Any tips or tricks in doing it would be appreciated.

thanks

You can do it.

Remove the rear seat and panels covering the rear quarter window area. Remove the stop bracket on the window mechanism. Remove the rubber shield at the top of the door jamb. Loosen the nuts on the track attaching studs, use a screwdriver to keep the studs from turning so you don't lose your adjustment.

Run the window all the way up, holding onto it firmly. The window will move forward and up. The three nylon rollers will glide right off the end of the track. There is one remaining roller, to the rear and top. Tilt the window and roll down if necessary to release the last roller from the stubby track on the glass.

See the '68 Fisher Body manual on my site for detail and illustrations.

Here is an excellent video on installing rear quarter glass in a 67/68 Firebird.