How do you unlock the four wheel drive?

To unlock 4 wheel drive on a vehicle will depend on the type of system the vehicle has. If it has a self locking hub, there should be a switch to turn from 4 wheel drive to 2 wheel drive. Always have the vehicle stopped before doing this. If the vehicle does not have self locking hubs, the vehicle has to be shifted to 2 wheel drive after the hubs are unlocked manually.