I aggree with scuffy on what he is saying.
As for replacing the the pump it is not that hard to do.
What I do is remove the aluminum mounting bracket with the pump attached to it.
All you have to do is remove the belt from the pulley, remove the lines attached to the pump. Then remove the three bolts holding the bracket to the engine. Then you can pull the pump and bracket out as one piece.
Then clamp the bracket into a bench vise. Using a power steering pump pulley puller remove the pulley. Then dismount the pump from the bracket. Then install the new pump.
Once everything is reassembled. Jack up the front end fill the reservior with fluid. If it was red when you removed the pump. You need to use dexron ( transmission fluid), if it was clear or yellow then you use power steering fluid. Once the reservior is full of fluid. With the engine off, you turn the tires full lock right, then full lock left. You keep doing this until all the air is bled out of the system.
The reason for jacking up the front end is to make it easier to turn.