How to Hide Simple Category List Admin Menus

function plt_hide_categorylist_menus() {
	//Hide the "Category lists" menu.
	remove_menu_page('nzp-scl');
	//Hide the "Category lists → All lists" menu.
	remove_submenu_page('nzp-scl', 'nzp-scl');
	//Hide the "Category lists → Add new" menu.
	remove_submenu_page('nzp-scl', 'nzp-scl-edit');
}

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

Where do I put this code?