1. Click the File tab.
2. Click 'Info' on the left column.
3. Click the 'Protect Document' icon under the Permissions heading.
4. Click 'Mark as Final' on the drop-down menu.
5. Click 'OK' on the pop-up that states, 'This document will be marked as final and then saved.'
6. Click 'OK' on the next pop-up menu, which confirms that the document has been marked as final.