1. Within the WordPress Dashboard, go the the Menu Settings
2. Make sure you select the "Main Menu" option
3. Click and expand the Custom Link Option from the different types of Menu Items
4. Enter in the URL you want the custom link to take the user to,
and give your custom link a label eg. "Registration"
5. Once you have done this, the custom link you just added will appear at the bottom of the Menu Heirachy
6. Click and Drag the custom link where you would like it to sit in the Menu's Heirachy.
7. Front end