The exact procedures to change the power steering pulley vary from car to car; The Project Asylum lists the procedures for changing the pulley off a Ford Taurus. A pulley installation and removal tool and a breaker bar are required.
Lubricate the pump shaft
Oiling the shaft allows the pulley to slip on easier and with less sticking points. Sticking points are points where a pressed part does not move without excessive force, which damages the pulley and tool.
Install the pulley
Use the breaker bar to hold the jack screw stationary and a wrench to turn the puller body. Put a wood dowel through a hole in the pulley to prevent it from rotating. Both the pulley and the jack screw must be secured to prevent damage to the tool or the pump shaft.
Remove pulley and polish bore a sticking point is reached
If a sticking point is reached that cannot be passed without excessive force, remove the pulley and use a fine polishing paper inside the pulley hole, removing a minute amount of metal. Clean and re-lubricate the pulley.
Repeat steps two and three until pulley is installed
The pulley will be fully installed when its flange meets the pump and the pulley is aligned with the other belted equipment.