AbleCommerce Shopping Cart Software

I can't figure out how to add a digital good to an order after the order has been placed. I want to give him something and associate it with the order so his downloads availablity is consistent.

But I can't find any place where I can assign a digital good to an order. The order details page has a digital good section but it's view-only. Thoughts?

I had to do it directly into the database in the orderitems table. It shows up on the order now and the customer hasn't complained and has downloaded it, so it must have worked OK.