Reply To: Rearranging the WordPress admin menu

[Rasmus Jürs]

I found the solution!

This little addition to the functions.php file removes the “nav-menu.php” link from appearance and adds it to the top level and moves it up under comments.

function remove_submenus() {
  global $submenu;
  unset($submenu['themes.php'][10]); // Removes Menu  
}
add_action('admin_menu', 'remove_submenus');

function new_nav_menu () {
    global $menu;
    $menu[99] = array('', 'read', 'separator', '', 'menu-top menu-nav');
    add_menu_page(__('Navigation', 'mav-menus'), __('Navigation', 'nav-menus'), 'edit_themes', 'nav-menus.php', '', '', 99);
}
add_action('admin_menu', 'new_nav_menu');

function custom_menu_order($menu_ord) {  
if (!$menu_ord) return true;  

return array(  
    'index.php', // Dashboard  
    'edit.php', // Posts 
    'upload.php', // Media
    'edit.php?post_type=page', // Pages
    'edit-comments.php', // Comments 
    'link-manager.php', // Links 
    'separator1', // First separator  
    'nav-menus.php', // Navigation
    'separator2', // Second separator  
    'themes.php', // Appearance  
    'plugins.php', // Plugins  
    'users.php', // Users  
    'tools.php', // Tools  
    'options-general.php', // Settings  
    'separator-last', // Last separator  
);
}  
add_filter('custom_menu_order', 'custom_menu_order'); // Activate custom_menu_order  
add_filter('menu_order', 'custom_menu_order');

Source:
http://wordpress.stackexchange.com/questions/9264/make-sub-menu-items-a-main-link-in-the-admin-menu-using-fuctions-php