Rich,
There is a slot in the bottom of the seal to stick the metal tab into. The glass piece can then be assembled into the seal. I used glycerin, an excellent rubber lubricant, to help installing the seals. Once the glass is in the seal, you can feed the bottom of the vertical part of the seal into the dual slots on the top of the "front guide channel" and slide the glass and seal down until the bottom of the horizontal seal meets the slot in the top of the door. From there on, it's pushing, shoving and squeesing until you can get everything seated.
The final struggle is installing the "protective cap" on the top of the front guide channel. It's a *****, but you can do it.
Here is a pic. I just took of the driver side of my car.
http://images.prosperpoint.com/1070/54506-94.jpg
Phil