Steps to change Office 2019 Product Key:
- On the device where you want to change the key, open any Office app, select the File menu and then select Account near the bottom of the menu.
- Under Product Information, select the Change License button.If there is no Change License button, you may need to install Office updates.
- Do one of the following:
- If you’re signed in, select Use a different account, and then select Enter product key instead.
- If you’re not signed in, select Enter product key instead.
- Enter your Office 2019 or Office 2016 product key, and then select Install this product instead.If your product key is new, follow the prompts to complete the redemption process.
- Office begins the update process. Close all Office apps to finish the process.