The Andersen Ultimate 5th Wheel Connection is likely your lightest option:
Ultimate 5th Wheel Connection
The B&W Companion hitch for its gooseneck installation comes out in 2 manageable pieces. I just set it down onto a furniture dolly and wheel it around. In fact, I need to yank mine out tonight for using my truck this weekend.
Other folks use hoists to engine lifts to get their fifth wheels in and out of their trucks.