Lay a lumber sheet on top of the dolly. It should cover the majority of the base.
Move the dolly next to the bathtub.
Position one person on each end of the tub. Position an additional one to two people on each side of the tub.
Grip the bottom of the tub. Lift it straight up. Rest it on its side on top of the lumber sheet on the dolly.
Lay down carpet or plywood pieces on the floors along the moving path.
Roll the dolly over the carpet or plywood, through any doorways and out to the moving truck.
Lift the bathtub off the dolly and onto the floor of the moving truck. Place a heavy blanket over the tub to protect it.