How do you replace 88 E-350 kingpins?

To replace the kingpins on a 1988 E-350, first, raise the front of the vehicle and secure it on jack stands. Remove the front wheels, brake components, and the steering knuckles to access the kingpins. Use a press to remove the old kingpins from the axle and install new ones, ensuring proper alignment and lubrication. Finally, reassemble all components, ensuring everything is torqued to the manufacturer's specifications before lowering the vehicle.