Not sure exactly how that is set up and since no on else is around to help I will give it my best shot without taking the trim panel off my scamp.
First there should be a metal piece that glues on to the bottom of the glass that needs to be on before you install the glass into the door. Second you do not have to remove the top post. If I am reading you right anyway. The glass goes front first down the opening and then make sure it's in the front channel then lower the back side in the hole and again make sure it's in the channel and about half way down twist the glass to make it's straight. you should be able to disconnect the regulator from the door and slide the rollers into the metal frame attached to the glass. Also insert the glass into the door from the outside of the window frame not the inside.
I's hard without sending you pictures but I hope that helped. Good luck.
