adding an item to a sale

[wayneq2013]

I need some help. I have a customer that purchased two of three items in a listing. I am now selling her the third with no shipping cost. She paid for the sale of the two items. How do I "sell" her the third item? I can't add to the invoice and don't know how to do this. 

Thanks for any help! 

[dhbookds · Accepted solution]

either put up another listing with "free shipping"  or if the original listing is still up with the one left, edit it to free shipping.   And then email her to buy it. 

[wayneq2013]

Thank you! I wasn't sure if there was another way to do it. Appreciate your help!