To add someone to your subscription, visit www.office.com/myaccount and follow the onscreen instructions to add a user. Each person you add will receive an email with the steps they need to follow. Once they have accepted and completed the steps, their information, including the installs they are using, will appear on your My Account page. You can stop sharing your subscription with someone or remove a device they are using at www.office.com/myaccount.
You must have the appropriate number of available subscriptions when adding a user, or the setup of a new user will fail.