How to Hide Post Types Unlimited Admin Menus

function plt_hide_post_types_unlimited_menus() {
	//Hide the "Post Types" menu.
	remove_menu_page('edit.php?post_type=ptu');
	//Hide the "Post Types → Post Types" menu.
	remove_submenu_page('edit.php?post_type=ptu', 'edit.php?post_type=ptu');
	//Hide the "Post Types → Taxonomies" menu.
	remove_submenu_page('edit.php?post_type=ptu', 'edit.php?post_type=ptu_tax');
}

add_action('admin_menu', 'plt_hide_post_types_unlimited_menus', 11);

Where do I put this code?