First, if any of the trucks in the junkyard have rear air, don't bother with the left side. The mounting is very different. Also, you'll need to drill holes through the floor for the bottom seat belt bolts. There's a welded on fixed nut on the underside of the vehicle for both rear seat belts that is not there in the 5 seat models.
It can be done but it time consuming. Make sure you remove every nut and bolt. Bring baggies and label everything. Remove the upper and lower interior panels as you'll need them as well as the upper interior D pillars.