Newbie with a window problem. Help!

I recently picked up a 1990 4Runner, and the rear window is a bit of a mess. It will go up and down, but moves about 2 inches, stops, 2 more inches, stops. The motor seems strong, but I need to use my hand to push it all the way back up. I read some of the other posts, and it seems it may be the "rusted track" issue, as there is some rust along the top edge of the tailgate. Any help would be greatly appreciated.

Also, I need to replace the black piece that runs around the top and sides of the rear window...I can't find a part # or any info online. Any idea where to find one, other than Toyota???

Thanks!

Try opening the tailgate then "latch" one of the latches, a screwdriver works good for this then the window can be rolled out BUT BECAREFUL the glass can break orut of its mount and be destroyed it will need to be supported!
See if it rolls up any easier outside the window frame, it is does there is an alignment bind or put some armour all on the rubber seal. armour all attracts dust though.
Good luck