Yes, the trans can be put in neutral without power...these trucks have no electric shift interlock like modern vehicles, these are 100% mechanical.
Key to the on position will unlock the column, shift it out of park by the shift lever. If no key or it's bound up internally, you can roll under and disconnect the shift linkage on the side of the trans and shift it from there.
Transfer case can shift by use of the floor shifter as long as there's no tension on the drivetrain.
If there's mechanical lock-up of any powertrain component that prevents freewheeling, the driveline(s) can be disconnected from the axles by removing 4 bolts and 2 straps, then tie up the end of the shaft to a structural undercarriage component with a ratchet strap. Ensure you tape the caps of the u-joint to ensure you don't loose any needle bearings.
How are you planning on transportating this beast? Transport trailer? Tow dolly? Flat towing with tow bar?
How far is your transport distance?
What are you using for a tow vehicle?
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