Update existing order?

Hi,

I'm wondering how I can go about achieving the following:

1) A user places a woocommerce order with formidable (with pay layer running, so the checkout hasn't been run yet)

2) They change their mind on a feature, and edit the form at the front end.

3) The woocommerce order is updated to reflect the new total

Perhaps a simpler version of this question is: How do I make it so that updating the formidable entry also updates the corresponding order? It seems like the order only ever contains the first submission, and doesn't update when I update the form entry.

Bonus question: How can I get the list of choices to be reflected in the checkout page?

Thanks in advance for any ideas,

Lachlan