Remove the vehicle's front wheels, detach the pinion shaft from the steering column, detach the tie rods, unbolt the rack from the chassis and disconnect the fluid lines. Disconnect the rack from the steering column and the pinion shaft. Remove and replace whichever one is damaged.
The process is similar for most cars, but it can be much more difficult on front wheel drive vehicles because of the location of the connecting bolts. Extracting the rack assembly can be complex and may require removal of other parts to get it free of the vehicle. Consult a service manual to see exactly what is required for the process on a specific car model.
Use a puller type tool to disconnect the tie rods and not a fork type. The fork tool can damage the grease seals. Measure the overall length of the rack and tie rods while they are connected. Set the new rack to the same size, or the steering wheel will be off-center.
Flush the power steering pump to remove particulate material when doing this type of repair. Use fresh fluid and bleed the lines by turning on the ignition until all air is removed from the system before reconnecting the lines.