How do you change out the ring and pinion on a c3500 truck?

To change the ring and pinion on a C3500 truck, first, lift the rear of the vehicle and secure it on jack stands. Remove the differential cover and drain the fluid, then unbolt and remove the old ring and pinion gears from the differential case. Install the new ring gear onto the differential case, ensuring it is properly torqued, and then install the pinion gear, adjusting the backlash and preload according to the manufacturer's specifications. Finally, reassemble the differential, replace the fluid, and test drive to ensure proper operation.