Attached is a diagram of the front of the Power steering pump loosen bolt B and pull or pry the pump down to get belt loose. Don't worry about bolt A if you tug hard enough it should swivel down far enough to get the belt changed.
Let me know if you need any further assistance.
Yes you will need to take off the AC/Alternator belt off first. Do you know how to do that?
Attached is a picture of the Alternator the top bolt or arrow is the bolt to loosen first you should be able to push or tap the alt. back to get the bolt loose. If not you will need to loosen the bottom arrow/bolt. this will allow th e alt to move then put belt on making sure they are lined up with the grooves and tight tension snug.
I hope this helps.