Rear quarter window on 40 tudor

[hope]

O.K. I was going to tackle that rear quarter window on my own, but looks like i'm going to need more than some words of encouragement, like the proper way to mate the glass and the window regulator.

I've got the glass set in the side channels, but anytime i try to mate the glass and the regulator no matter how i slide either one up or down seems impossible to get a near fit.
Is it better to have the arms of the regulator cranked all the up or down?
Thank to anyone that replies.