Before doing anything else, find the window run position and put the A-pillar section into the door through the belt line, slowly guiding it down by the molded corner. After that, set the top corner of the B-pillar into the window run, moving it up until it seats on the header, but try not to press it too hard and damage it. Fit the entire B-pillar part into the tracks, then add the header glass piece, watching carefully to ensure both aren't displaced. Set the corner of the A-pillar into the window run, slide it upward to the point where the rubber part of your mold touches the frame and snap both parts together at the top of the channel. Next, secure the header portion of the door glass in place from the A-pillar right to the B-pillar, making sure everything is correctly aligned as you work. After that, fit the inner belt
Weather Strip and the door trim panel.