Код

function remove_loop_button(){
remove_action( 'woocommerce_after_shop_loop_item', 'woocommerce_template_loop_add_to_cart', 10 );
remove_action( 'woocommerce_single_product_summary', 'woocommerce_template_single_add_to_cart', 30 );
}
add_action('init','remove_loop_button');