How To Remove Products Images Placeholder in Woocommerce

Hello
I use your awsome theme, but also with your child theme. My problem right now is I am working to create a product in woocommerce and I need to remove products images placeholder. I followed a lot of tutorials from web but I really don"t know how manage in child"s theme functions.php adding this snippet:

remove_action( 'woocommerce_before_single_product_summary', 'woocommerce_show_product_images', 20 );
I tried to insert on different line this code, but without succes. Can anyone help me, please? Thanks