Use the gettext WordPress filter to change any translatable string.
<?php
/**
* Change text strings
*
* @link http://codex.wordpress.org/Plugin_API/Filter_Reference/gettext
*/
function my_text_strings( $translated_text, $text, $domain ) {
switch ( $translated_text ) {
case 'Sale!' :
$translated_text = __( 'Clearance!', 'woocommerce' );
break;
case 'Add to cart' :
$translated_text = __( 'Add to basket', 'woocommerce' );
break;
case 'Related Products' :
$translated_text = __( 'Check out these related products', 'woocommerce' );
break;
}
return $translated_text;
}
add_filter( 'gettext', 'my_text_strings', 20, 3 );