Log in to your WordPress website's dashboard and click the Add or Change Navigation Menu link under the SITE PAGES section.
Alternatively, hover over "Appearance" on the left and select Menus.
From this screen, ensure that "Main Navigation Menu" is selected as the menu to edit at the top.
Below this field, you'll see the list of all your site's pages on the left, and the drag-and-drop menu editor on the right.
To edit an existing menu item, click the downward arrow on the right of its tab and change it.
To delete a menu item, click the downward arrow on the right of the tab and click the REMOVE link.
To change a menu button's position, simply drag it where you want it to go. Indented tabs here are the drop-down submenus on your website, while left-aligned tabs are top-level menu tabs.
To add a new page to the menu, check the box on the left-hand column next to the page you want to add. It will appear at the bottom of the right-hand column, where you can drag it where you want it to go on the menu.
Click the SAVE MENU button in the upper right to make your changes permanent.