Farranger....
Johnwill is essentially right, but I have a question and a few additional comments.
First, is this single-action or double-action? If it is single, it is a Mustang, but if it is a Pony, then it is actually DAO.
I just bought a Pony PocketLite from a dealer who used to work for Colt, in fact he helped develop this pistol, and he taught me the correct way to dissassemble/assemble it.
You first remove the magazine and check for any chambered rounds (DUH! I knew you knew this, but old safety habits die hard). Then rack the slide back until the slide-stop cutout on the slide lines up with the slide stop (I am doing this from memory so I hope I am using the correct terms). Hold the pistol in your right hand in this position (by placing the pistol in the palm of your right hand and curling the fingers over the top of the slide), and reach under the pistol with your left hand to pop out the slide stop from the right side of the slide (to avoid scratching the finish).
On a new pistol, the barrel is a bit hard to take out of the slide so he advised to tap on the end of the barrel with a plastic or rubber mallet to dislodge it.
You then clean it, and place a small amount of oil or lubricant at the front of the rails and the top of the guides at the rear of the frame. Reassemble in reverse order and insure that the guide rod is not sticking out too much or the barrel and spring may not be assembled correctly.
I hope this is clear, if not, let me know and I will try to do better.
Hope your wife likes her new pistol.