How to Hide WP Ultimate CSV Importer Admin Menus

function plt_hide_wp_ultimate_csv_importer_menus() {
	//Hide the "Ultimate CSV Importer Free" menu.
	remove_menu_page('com.smackcoders.csvimporternew.menu');
	//Hide the "Ultimate CSV Importer Free → Ultimate CSV Importer Free" menu.
	remove_submenu_page('com.smackcoders.csvimporternew.menu', 'com.smackcoders.csvimporternew.menu');
	//Hide the "Ultimate CSV Importer Free → Manage Addons" menu.
	remove_submenu_page('com.smackcoders.csvimporternew.menu', 'wp-addons-page');
}

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

Where do I put this code?