This wikiHow teaches you how to update Microsoft Office on a Mac. You can easily check for and install updates from the Help menu of any Microsoft Office product.
Steps

Step 1. Open any Microsoft Office application
You can open Microsoft Word, Excel, Outlook, or PowerPoint. To access any of the Office applications on a Mac, click on the desktop and then click To go in the menu bar at the top. Then select Applications in the drop-down menu.

Step 2. Click Help
It's in the menu bar at the top of the screen.

Step 3. Click Check for updates
It is the third option on the Help menu.
- If you don't see the "Check for updates" option in the Help menu, Click here to download the latest version of the Microsoft AutoUpdate tool.

Step 4. Select "Download and install automatically"
It's the third radio button option under "How do you want updates to be installed?" in the Microsoft AutoUpdate tool.

Step 5. Click Check for updates
It's in the lower-right corner of the Microsoft AutoUpdate tool. This action will check for the latest Microsoft Office update and install the updates.