I think it was made clear by engatwork - install the seal on the glass, install the aluminum trim into the groove in the seal, install the assembly. I lube the seal with dish detergent - it is slippery and washes off easily.

I suggest a new, factory, not aftermarket, seal.

Any cord about 3-4 mm in diameter will work. I use some cotton cord that I coated with candle wax - it makes the cord slide easier. Pull the coed parallel to the glass.