On a Mac, our Office File tab is up by our Apple button and looks pretty different from the Windows OG. But we can still do all the necessary steps.
Macs automatically update your file when you save it. Simply save the file with the most recent extension type (.docx for Word).
If you aren't sure of the extension, click File > Properties > General. You'll see the file name and its extension. If it's out of date, there will be an Update button.
To erase or modify the properties (author, title, etc), go File > Properties > Summary.