1989 Dodge Xplorer

The unit mounts on two rails that act as skids supporting the fridge off the floor. From the rear you'll have to disconnect the gas line and the electrical. That will be a challenge as the connection block is just below the ac outlet and is exposed to weather and will have corroded the fittings. Soaked in Rust Blaster or some other rust loosener before/preferable overnight, will go a long way to easing the loosening and salvaging the connection. Remove the fridge door to reveal the few screws if any that originally stabilize the unit in place. Previous owners may have removed them as you indicated that silicon is visible and that is not original. It will slid out into the living space and can be maneuvered out the passenger door very easily with the passenger seat removed. The base of the seat can stay but you'll need to jury rig something to keep the base of the fridge from hanging up as you maneuver over the seat pedestal.