If you don’t need a dropdown or mega menu then it’s very simple to you. Just open _partials/ folder and then delete the current navigation file and then rename**navigation-regular.hbsfile tonavigation.hbs**

Now re-upload the modified zip package of your theme and then set up the navigation items from the admin panel.

https://support.themeix.com/wp-content/uploads/2021/07/setting-ghost-1024x473.png

Under settings>navigation, you will see the primary navigation area,

Just update the navigation menu items there.

https://support.themeix.com/wp-content/uploads/2021/07/image-1024x317.png