You cannot delete or replace the Ribbon with the toolbars and menus from the previous versions of Microsoft Office. However, to make more space available on your screen, you can minimise the Ribbon.

1. From the Quick Access Toolbar, click Customize Quick Access Toolbar .
2. From the drop down list, select Minimize the Ribbon.  

To use the Ribbon while it is minimised, click the tab you want to use, and then click the option or command you want to use. After your request has been performed, the Ribbon reverts to being minimised.