Hi lola_d
Thanks for your post.
As long as you haven't recorded a receive items transaction or deposit against the order, you could raise separate bills as you receive items and then delete the order when you've received everything.
Another way to do it, that may be easier, would be to select the order and click change to bill. On the bill, deduct in 'bill' column any items you haven't received, and type the amount for those items in the 'back-order' column instead. This will convert the order to a bill, with only the items you've been billed, and create a new order for the remaining items. If you use receive item transactions, or pay deposits to suppliers, this would be the way you'd need to record the transactions, otherwise, either method would work.