function ship_to_different_address_translation( $translated_text, $text, $domain ) {
switch ( $translated_text ) {
case 'Ship to a different address?' :
$translated_text = __( 'New Text', 'woocommerce' );
break;
}
return $translated_text;
}

add_filter('gettext', 'ship_to_different_address_translation', 20, 3);