The reason I wanted to install a new door lock was because my Bighorn 2006 key opened not only all 2006 models but 2007 and 2008.  I just didn't feel real secure with the door locked.

The only advice I can give about installing a residential door lock is make sure the RV door is thick enough for the lock you are installing.  You will find some lock minimum door thickness is more then the RV door.  So measure the door first and read the lock instructions before buying. As for the actual installation follow the instructions that came with the lock.  The pictures below are outside door view, inside door view, deadbolt in the door, and door frame.