There are two main reasons you would deactivate an Office 365 installation:
You’ve shared your Office 365 Home subscription, and you want to deactivate an install for someone using your subscription. Deactivating someone’s install isn’t the same as removing that person from your subscription. If you want to completely remove someone from your subscription, you can.
You've run out of Office 365 installs. So you deactivate one so you can install Office on a different PC, Mac, or tablet.
After you deactivate an install, you’ll still be able to view and print documents but you won’t be able to edit them or create new ones. Office lets you know that the install is deactivated by showing Unlicensed Product notifications.
If you actually want to remove Office, you can by following the steps in one of these articles: Uninstall Office 2016, Office 2013, or Office 365 from a PC, Uninstall Office 2016 for Mac, or Uninstall Office 2011 for Mac.
Watch the video or follow the steps below the video to learn how to deactivate an Office 365 install.
On your My Account page, choose Install.
On the Install page, choose Deactivate Install next to the name of the computer or tablet that has the install you want to remove.
Choose Deactivate to confirm that you want to deactivate this install.
After you deactivate an install, Office will run in read-only mode on that computer or tablet. That means you’ll be able to view and print documents but you won’t be able to edit them or create new ones.