function plt_hide_advanced_import_menus() {
//Hide the "Appearance → Demo Import" menu.
remove_submenu_page('themes.php', 'advanced-import');
//Hide the "Tools → Advanced Import" menu.
remove_submenu_page('tools.php', 'advanced-import-tool');
}
add_action('admin_menu', 'plt_hide_advanced_import_menus', 11);