Remove or change the Microsoft Office serial number
The official way to remove or change the serial number for the Macintosh version of Microsoft Office is to use the “Remove Office” tool. This program uninstalls Microsoft Office from your computer. It comes on your Microsoft Office installation disc. It is also available in the “Additional Tools” folder in the Microsoft Office installation (as of Microsoft Office 2004).
Once you use the “Remove Office” tool to uninstall Office, you can re-install it with a new serial number, if needed.
Alternately, a “De-serialize Microsoft Office” script is available from a Microsoft MVP. We do not support the use of this script; use it at your own risk.
You may need to go through these steps if your new Macintosh computer came with a Microsoft Office trial pre-installed. If you later need to install a full copy of Office, you must remove the trial edition first.