Free Shipping Label

I’m trying to add a FREE SHIPPING – prior to all shipping methods that are free but i can’t seem to get it working.

This is what I’m adding to the functions.php file, any help would be great!

add_action( ‘WC_Shipping_Method’, ‘free_shipping_methid_update’ );

function sww_wc_free_shipping_label( $label, $method, $method_title) {
if ( 0 == $method->cost ) {
$label = ‘<span class=”freeshippinglabel”>Free shipping! – </span>’ .get_method_title ($title);
}
return $label;
}
add_filter( ‘woocommerce_cart_shipping_method_full_label’, ‘sww_wc_free_shipping_label’, 10, 2 );