tnfaulksr, go to the Firestone Ride-Rite website
Do a "vehicle search" to make sure they fit model to model. Check the chart for your year and model and then of the sellers vehicle and model. The part (kit) numbers will probably be the same. If they are, these are pretty easy to install. Just make sure the bags were not damaged on removal and that you have all of the parts. As john5646 states, a new kit is $225. A bag replacement is about $100. They are well worth the $225-cheap is better if they are in good shape.
I believe that you can get the mounting instruction from Ride-Rite for your TV as-well. Mounting varies slightly from vehicle to vehicle, but no drilling of holes is required.
I removed a set of Ride-Rites from an '08 Sierra and wanted to put the on a 2013 Silverado. Basically the same bodies. However, the part numbers did not match, so I ordered a set for the Silverado. When the new ones arrived, I compared them with those from the Sierra. The only difference was that the top mounting hole was oval on the new ones and round on the older set. The new set would fit the '08 Sierra and the '13 Silverado, but the older set hole would have to be made oval and the would have fit. Had I known that, I could have saved some money and just reamed the holes oval by a quarter inch.