How to Hide the "Rename Taxonomies" Admin Menu

function plt_hide_rename_taxonomies_menus() {
	//Hide the "Tools → Rename Taxonomies" menu.
	remove_submenu_page('tools.php', 'rename-taxonomies');
}

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

Where do I put this code?