tester_remove_fields_from_before_button.php

<?php
/**
 * Move add-on fields below the add to cart button
 */
function tester_remove_fields_from_before_button() {
	remove_action( 'woocommerce_before_add_to_cart_button', 'pewc_product_extra_fields' );
	add_action( 'woocommerce_after_add_to_cart_button', 'pewc_product_extra_fields' );
}
add_action( 'init', 'tester_remove_fields_from_before_button' );