I helped a guy change mine out, he got in the cab and started pushing on the pass. corner with his feet and started pushing the original glass out, then he took the new sliding glass and put the original seal around it then cut a long piece of wire (about 1/8 dia) and wrapped it all the way around the seal with the glass in it. Then he lubed it real well with dishwashing liquid (Joy). The two loose ends of the wire met at one corner, then as he started that corner in, he pulled on one of the loose ends of the wire (which pulled the seal into the cab), while i helped hold it and pushed in from the bed of the truck. It seemed easy enough but he had done it before. You may want to consider having it done professionaly.