You will need to reach up inside the cab corner between the inner & outer panels to remove the nuts. I seem to recall the older (wider) pre-'81 having 2 nuts & the later ones only having one per corner, but feel carefully to be sure you got them all. The ends will slide out of the center part with a little wiggling & effort. The long portion is held on with plastic clips. You can look in the end of the molding to figure if you need to pry out on the bottom or top first. If you can't tell, try sliding the trim one way to expose a clip to see it better. With a tap of a hammer or small piece of wood, the clips will come off of the studs. Install on your truck in the reverse order. Lorne