This document will explain how to delete a menu item.
Click on 'Menus':
For this example, we will located and remove a menu choice for Matcha tea that we are no longer offering for sale. So, we first click the menus choice in the Storefronts admin menu then we scroll down to the "Header Menu" then we locate the Matcha submenu to the Teas menu choice. To remove Matcha from the menusimply click the red trashcan icon along the right side of the Matcha menu choice:
View of the menu after deleting "Matcha" from the menu: