The three buttons displaying at the top right hand side of your website are managed under Content > Link Lists. The followig Link Lists are used:

• Watch Now Button: controls the first button for "Watch Now"
• Top Nav Button 1: controls the second button for "I'm New"
• Top Nav Button 2: controls the third button for "About Us"

Within each Link List, you will see one item listed for the respective button. Click the pencil icon to edit the button title, link and icon.