How to remove door glass/vent window in 1968 barracuda?

I have a Haynes manual that isn't very good explaining how this is done properly. I have removed lower nut to front track, regulator and lift bracket dropped from glass, bolt and nut to upper front of door. What am I doing wrong here? The glass won't slide out do to top of vent window in the way also. I need to remove the vent window and door glass can anyone clue me in to this assembly? Again this is a 1968 barracuda.