Decide on the best place for the dish and attach it to the roof of the RV. Keep in mind the space that is needed to fold your dish down and to rotate it to get a signal. Give enough space but try to minimize the distance that the coaxial cable will have to run as excess length can degrade the signal. Often times attaching a satellite dish to an RV will include screwing a mounting plate to the roof which will require a drill, screws and a screw driver. Be sure to caulk around the screws to prevent leakages. Most satellite dishes that are specifically for RV usage fold down or come apart to avoid damage while traveling.
Attach the RG-6 coaxial cable to the satellite dish. Usually this connects to the LNB and is included in the satellite dish installation kit. If it is not then the cable can be bought at most hardware, home improvement and electrical stores. The connectors that fit on the end of the cable and into the LNB jack may have to be fitted on as well. Ones that screw on are usually the most cost effective and avoid the need to purchase a special cable crimping tool.
Run the cable down from the satellite dish to an outside, weatherproof connector jack on the side of the RV. Many newer RV's have this already, but you may need to install one on older models. An easier, more temporary, way is to run the cable through an open window.
Run the cable either from the open window or from the inside of the connector jack to the receiver box that should come with the satellite dish. The cable fits into the SAT IN slot in the back of the receiver. The receiver should be located in a dry safe place where its air vents won't be obstructed. If the remote control that came with the receiver uses IR (Infrared) to send signals back and forth, you should place the receiver where the remote can be pointed at it in a clear line of sight. If the remote uses RF (Radio Frequency) this is not an issue, and the receiver can be placed in a cupboard if desired.
Run the RG-59 coaxial cable from the TV OUT slot in the back of the receiver to the TV. Use only as much cable as is necessary as excess cable may weaken the signal.
To get a picture on the TV the satellite dish must be positioned correctly to pick up a signal from the satellite. The manual that came with the satellite dish will give instructions on how to do this correctly.