Move the Office for Mac 2011 applications to the Trash. After you have completed the removal, empty the Trash then restart your Mac.
Be sure to close all Office for Mac 2011 applications before you delete them. While you do this, close all Office applications.
Remove the Microsoft Office 2011 folder
-Open Finder > Applications
-Drag the Microsoft Office 2011 folder into Trash.
-Restart your computer.
Find more detailed solution here Does Microsoft office expire