How do I rename person in Photos

How do I Rename a person (face) in Mac Photos; also known as, how to fix the name of a person which now has the wrong name in Apple Photos.

The answer is to open the person's People page. Then in the upper left corner on the name, click on the name which should be highlighted in blue. A new window will pop up and prompt you to select the correct name for the person from your list of Contacts.

Today, the AppleCare support team incorrectly told me this rename could not be done. They told me to remove the person and retag the person. After I declined to remove the person, I simply followed my instincts and clicked on the name of the person, since it was in blue, and I've learned that Apple makes a field blue when you can click and change it, in many of their newer apps.

There were 800 pictures associated with the wrong name, and this fix worked for me. I hope it helps you too.