Wordpress. Change text using gettext function.

wp_change_text_with_gettext.php

add_filter( 'gettext', 'change_woocommerce_return_to_shop_text', 20, 3 );
function change_woocommerce_return_to_shop_text( $translated_text, $text, $domain ) {
  switch ( $translated_text ) {
    case 'Return to cart' :
    $translated_text = __( 'Back to Shop', 'woocommerce' );
    case 'Return to basket' :
    $translated_text = __( 'Back to Shop', 'woocommerce' );
    break;
  }
  return $translated_text;
}