You may change your current Basic, Pro, or Pro+ Edition license key to a new or alternative key by following the instructions in this article. This can be required if your company has combined many product keys into one. You may deactivate the current license and reactivate it with a new product key by following these instructions if you have Office Timeline version 3.9.5 or more:
Launch PowerPoint, then choose the Office Timeline tab. Here, choose Deactivate the machine under Help.
When asked to deactivate your license, choose Yes. This will turn Office Timeline back to Free Edition mode and delete the current license from your machine.
The Office Timeline page will display the Upgrade and Activate buttons as soon as you successfully deactivate your device. To see the product activation dialog box, click Activate.
To activate Office Timeline, copy it or put in your new product key and click the Activate button.