Modifica el texto de aviso de stock en la ficha de producto

wc-custom-stock-message.php

// Personaliza texto stock bajo
add_filter( 'woocommerce_stock_html', 'custom_stock_message', 10, 3 );
function custom_stock_message( $availability_html, $stock, $product ){

  $num_items_in_stock = $product->total_stock;
  $availability = $product->get_availability();

  if ( $product->total_stock <= get_option( 'woocommerce_notify_low_stock_amount' ) ) {

    $new_availability_html = '<p class="stock" style="color: #EA4242;margin-top: 5px;"> ¡Date prisa! Solo nos quedan ' . $num_items_in_stock . ' unidades</p>';
  }else{

    $new_availability_html = empty( $stock ) ? '' : '<p class="stock ' . esc_attr( $availability['class'] ) . '">' . esc_html( $stock ) . '</p>';
  }

  return $new_availability_html;
}