Replace WooCommerce Class

WooCommerce has a class “get_shipping_to_display()”, that keeps outputting $36 in my invoices (using the Print Invoice & Packing List plugin) as the value for shipping… regardless of what the shipping out is actually.

I’ve narrowed it down to that class, as using “get_shipping()” displays the actual shipping price.

I don’t want to modify WooCommerce core files (so as not to cause problems with updates later on), so how do I go about replacing that class with my own class in functions.php… and what would that look like?

Thanks!

http://wordpress.org/plugins/woocommerce/