I really don't like to hate on peoples work, But..
The fluid spec is Mercon V, Use such, And no "PSF is the same as ATF".
Second, a more thorough way to do things and as the way the Ford service manual states is to remove the fluid from the reservoir and disconnect the line feeding the pump from the front of it, hook on a plastic tube to a catch container and either, jack the front up and turn the steering wheel with the engine off, or turn the engine on and as its pumping the fluid out, you keep adding fresh. After about 2.5-3 quarts, its ALL changed.
While this is a valid way of doing it, its just really slow and inefficient.