How to Hide Courier Notices Admin Menus

function plt_hide_courier_notices_menus() {
	//Hide "Tools → Scheduled Actions".
	remove_submenu_page('tools.php', 'action-scheduler');

	//Hide "Courier Notices".
	remove_menu_page('edit.php?post_type=courier_notice');
	//Hide "Courier Notices → All Notices".
	remove_submenu_page('edit.php?post_type=courier_notice', 'edit.php?post_type=courier_notice');
	//Hide "Courier Notices → Add New notice".
	remove_submenu_page('edit.php?post_type=courier_notice', 'post-new.php?post_type=courier_notice');
	//Hide "Courier Notices → Design Studio".
	remove_submenu_page('edit.php?post_type=courier_notice', 'http://127.0.0.1/wp-admin/edit.php?post_type=courier_notice&page=courier&tab=design&subtab=global');
	//Hide "Courier Notices → Settings".
	remove_submenu_page('edit.php?post_type=courier_notice', 'courier');
}

add_action('admin_menu', 'plt_hide_courier_notices_menus', 11);
Where do I put this code?