I found these instructions on Microsoft's support site. - Not sure if I am allowed to post them here...

Upgrade to Office for Mac (subscription version): If you're a volume licensed customer of Office 2016 for Mac or Office 2019 for Mac, you can upgrade to Office for Mac (available with certain Office 365 or Microsoft 365 plans) without uninstalling your current version. First, download and run the license removal tool. Second, launch Microsoft. Uninstall Office 2016 is licensed under the MIT License - see the MIT License for details. About This script allows you to uninstall or automatically delete Office 2016, 365 or earlier using the Microsoft Windows command line. Remove Office for Mac applications Open Finder Applications. Command +click to select all of the Office for Mac applications. Ctrl+click an application you selected and click Move to Trash.

Remove Office 2016 for Mac applications

From Microsoft support page - https://support.office.com/en-us/article/Troubleshoot-Office-2016-for-Mac-issues -by-completely-uninstalling-before-you-reinstall-ec3aa66e-6a76-451f-9d35-cba2e14 e94c0

IMPORTANT Follow the steps in this article only if you've tried the usual Office for Mac uninstall process and are still having difficulty reinstalling or starting Office applications.

To completely uninstall Office 2016 for Mac you must remove the applications, supporting files, and keychain entries, plus any icons you've added to the Dock. Once you've removed everything, empty the Trash and restart your Mac to complete the process.

Office 2016 Mac License Removal Tool Removal

You must be signed in as an administrator or provide an administrator name and password to complete these steps.

There are several things to remove. This article steps you through each one.

Step 1: Remove Office 2016 for Mac applications

Mac License Removal Tool

1. Open Finder and click Applications.
2. Command +click to select all of the Office 2016 for Mac applications
3. Ctrl+click or right-click the applications you selected and click Move to Trash.

Step 2: Remove supporting files from the Library and User folders

Remove files from the Library folder, you'll need to first set the Finder View options.

1. Open Finder, click Go > Computer, and then click View >as Columns.
2. Go to Macintosh HD > Library > LaunchDaemons.
3. In the LaunchDaemons folder, ctrl+click or right-click this file if present, and then click Move to Trash.

   com.microsoft.office.licensingV2.helper.plist (if present)

4. Go to Library > PrivilegedHelperTools, ctrl+click or right-click this file if present, and then click Move to Trash.

   com.microsoft.office.licensingV2.helper (if present)

5. Go to Library > Preferences and ctrl+click or right-click this file if present, and then click Move to Trash.

   com.microsoft.office.licensingV2.plist (if present)

Remove files from your user Library folder

To remove files from your user Library folder, you'll need to first set the Finder View options.

1. In Finder, press +Shift+h.
2. On the Finder menu, click View > as List, and then click View > Show View Options.
3. In the View Options dialog box, select Show Library Folder.
4. Switch back to Column view (+3) and click <YourUserName>Library > Containers and ctrl+click or right-click each of these folders if present, and then click Move to Trash.

5. Switch back to Column view (+3) and click <YourUserName>Library > Group Containers and ctrl+click or right-click each of these folders if present, and then click Move to Trash.

Step 3: Remove Keychain Entries

Open Finder > Applications > Utilities > Keychain Access and remove the following password entries:

2. Search for all occurrences of ADAL in the keychain and remove all those entries if present.

Step 4: Remove Office 2016 for Mac icons from the Dock

If you added Office icons to the Dock they may turn into question marks after you uninstall Office 2016 for Mac. To remove these icons, control+click or right-click the icon and click Options > Remove from Dock.

Step 5: Restart your computer

When you've removed all the files listed in this section, empty the Trash and restart your computer.

If you plan to reinstall properly See Also

Nov 8, 2015 7:10 PM

To uninstall Office 2016 for Mac, move the applications and user preference files to the Trash. Once you've removed everything, empty the Trash and restart your Mac to complete the process. You can also perform a complete uninstall for Office 2016 for Mac if you are troubleshooting an issue.

You must be signed in as an administrator on the mac or provide an administrator name and password to complete these steps.

1. Remove Office 2016 for Mac applications

1. Open Finder > Applications.

2. Command +click to select all of the Office 2016 for Mac applications.

3. Ctrl+click an application you selected and click Move to Trash.

2. Remove files from your user Library folder

To remove files from your user Library folder, you'll need to first set the Finder View options.

1. In Finder, press +Shift+h.

2. On the Finder menu at the top, click View > as List, and then click View > Show View Options.

3. In the View Options dialog box, select Show Library Folder and save.

4. Back in Finder, open Library > Containers and ctrl+click each of these folders and Move to Trash. Not all of these folders may be present.

   • com.microsoft.errorreporting

   • com.microsoft.Excel

   • com.microsoft.netlib.shipassertprocess

   • com.microsoft.Office365ServiceV2

   • com.microsoft.Outlook

   • com.microsoft.Powerpoint

   • com.microsoft.RMS-XPCService

   • com.microsoft.Word

   • com.microsoft.onenote.mac

5. Warning: Outlook data will be removed when you move the three folders listed in this step to Trash. You should back up these folders before you delete them.

   Click the back arrow to go back to the Library folder and open Group Containers. Ctrl+click each of these folders if present, and Move to Trash.

   • UBF8T346G9.ms

   • UBF8T346G9.Office

   • UBF8T346G9.OfficeOsfWebHost

3. Remove from dock and restart

1. If you put any of the Office applications in your dock, go to each one and ctrl + click > Options > Remove from Dock.

2. Restart your Mac to complete the uninstall.

*Reference: https://support.office.com/en-us/article/uninstall-office-2016-for-mac-eefa1199-5b58-43af-8a3d-b73dc1a8cae3