I put the regulator in the bottom of the door, tipped the glass in from the top, lowered it down, engaged the the arms in the tracks, wound the the regulator to the window to the almost full up position, lifted everything up until the crank pin fit thru the hole, installed the mounting screws, wound the window down until I could install the roller stud thru the hole in the door, and wound it up and down a few times. I had the original regulators for the doors and the single sheet metal "locking" screw ended up lined and I installed it as the last step.