The Remove link, 
, appears next to any extension names that you are authorized to uninstall.
To uninstall an extension:
From the Smart View ribbon, select Options, and then Extensions.
Click the Check for updates link.
Smart View checks for any extensions that can be removed.
In the extensions list, locate the extension to uninstall and click the Remove link,
.You are prompted that the extension will be uninstalled when the Office application is restarted.