There is no way to delete or replace the Ribbon with the toolbars and menus from the earlier versions of Microsoft Office. However, user can minimize the Ribbon to make more space available on your screen.
How to Hide the ribbon?
To minimize the Ribbon, simply right click on any place of the Ribbon. A menu pop-up and check (click) the minimize the ribbon. The ribbon will be minimized.
How to Restore/Show the ribbon?
Now, if needs to restore or show the ribbon, simply right click on the menu bar or home button and click the minimize the ribbon to remove the check mark. The ribbon will be visible.