Finally the solution is to edit lines number 162 and 163:

<label class=”screen-reader-text” for=”s”><?php _e( ‘Buscar productos…’, ‘woocommerce’ ); ?></label>
<input type=”search” class=”search-field” placeholder=”<?php echo esc_attr_x( ‘Buscar product
os…’, ‘placeholder’, ‘woocommerce’ ); ?>” value=”<?php echo get_search_query(); ?>” name=”s” title=”<?php echo esc_attr_x( ‘Buscar productos…’, ‘label’, ‘woocommerc
e’ ); ?>” />

I changed Search Products for Buscar productos.