How do you replace window regulator in 70 Blazer?

[JWPOORE]

I need to replace my driver's side door regulator, and had to use vice-grips to roll it completely up. In the repair manual, it only says to roll up the window, remove the 4 screws and slide out the regulator and then do the reverse to install the new one. It does not say how the window lines up inside, does it fall to bottom once the regulator is removed, and basically is kind of vague on how this really needs to be done completely.

I saw a write up on here, but can't find it now on someone who replaced one on a 69-71 Truck it think, but they removed the vent window and I believe rolled the window down, so I am confused on this because I am not sure which way I need to go about doing this and if removing the vent window is necessary on a Blazer - hopefully not .

Any feedback or illustration on this would be greatly appreciated. Thanks!