I did on our Georgetown. Winegard Trav'ler automatic dish. I assume you are talking about a dome with the constant tracking but the idea is the same. For us the wiring for the dish was under a cap on the roof in the front right corner (above the passenger seat) and it looks like a vent cap for plumbing. There is a single screw that needs to be removed (it may be under a blob of caulking) to remove the cap. Once off you can see the coax cable under there.
Make sure the dish you are considering can receive the new HD channels as the dish networks are moving their HD programming to satellites that the older domes cannot receive.