First remove the coolant overflow container then unbolt fuse centre and push aside. Next remove the serpentine belt and put aside (note the routing).
Put an oil pan under the pump. Remove the fluid line from the bottom of the pump with a stubby wrench. Remove the return hose by compressing the clip with a pair of pliers. Allow to drain fluid as much as possible.
There are two bolts that secure the pump to the block (one on the top one on the bottom). Using a deep socket line up the hole on the pulley with the bolts and remove the bottom one first then the top. Pull the pump up and out of engine bay near the firewall and strut mount (its tight but it will come out).
Take the pump to your local service centre to have the pulley removed from the dead pump and installed on the new pump. Don't try to pry it you will only damage the pulley. A pulley puller/installer must be used.
Installation is the reverse but is easier from the bottom as you can see the bolt holes.
Top off the fluid using standard GM power steering fluid which is available at GM dealers.(requires a funnell with a long flexible neck)
Replace the serpentine belt (use a new one).
Reinstall coolant overflow and secure the fuse centre.
Power wash the engine to get rid of any spilt fluid as it is very flamable.
Start the car and with both wheels off the ground turn the wheel left to right several times. Confirm that there are no leaks.
That's it drop the car and go for a test drive.