How to take a door apart

Ok,so I busted out my passenger side vent glass last week and I found a complete replacment (NOS genuine gm)for my 78 gmc and I took off the door panel,unbolted the vent glass frame from the door frame in all 4 places and even unbolted the regulator and now im stuck…the vent glass frome still wont come out.It looks like my only option is to take the freakin door apart:-(If anyone knows what i can do please steer me in the right direction and Ill be eternally grateful