Remove nav menu item by script

Question

I want to create my custom nav menu using a script in a wp plugin. I'm almost there using this tutorial. All I need is the option to delete menu entries.

something like wp_delete_nav_menu_item($menuID, $itemID);

As an alternative, I could create a new menu using wp_create_nav_menu($menu_name); so I don"t have to delete the default entries of the menu I would be working with otherwise. The problem here is, that the theme gives options for the position of the menu like 'header' and I dont know how i can define a position for a newly created menu.

Hope someone can give advice so I can solve one of these issues. Thanks!

This is the code I am working with so far. I need the code for the part to delete the default entries

//Add Menu
//Get Menu ID
$mymenu = wp_get_nav_menu_object('Header');
$menuID = $mymenu->term_id;

//Check if Menu exists
if( !$mymenu ) {
    //Menu exists -> Delete the default entries
    //
} else {
    //Menu does not exist -> Create it
    $menuID = wp_create_nav_menu('Header');
}

//Create new Menu Entries
//Create Parent Menu Entries
$myPage = get_page_by_title( 'Home' );
$itemData =  array(
'menu-item-object-id'   => $myPage->ID,
'menu-item-parent-id'   => 0,
'menu-item-position'    => 1,
'menu-item-object'      => 'page',
'menu-item-type'        => 'post_type',
'menu-item-status'      => 'publish'
);
wp_update_nav_menu_item($menuID, 0, $itemData);

Answer 1

Here you go.

//This code will register a Location with wordpress.
//You can assign menu to this location.
add_action('init','register_my_menu');
function register_my_menu(){
    register_nav_menus(array(
        'header_navigation' => 'Header Navigation'
        ));
}

But we haven't defined any location in theme yet.

This code will be used in theme where you want your menu to get rendered.

<?php

wp_nav_menu($menu_args);
    $menu_args = array(
        'theme_location'=> 'header_navigation', //slug from the previous code.
        'container'     =>  true,   //if you want a div around your menu.
        'menu_class'    => 'nav',   // It will add the class name of menu <ul>
        );
 ?>