How to change the qty or price on an order that has been invoiced
1. Open the invoice associated with the sales order
2. Void the invoice by clicking the Red 'Delete' button on the right side of the screen (Red 'X' symbol). This will unbill and unship the sales order.
3. Open the original sales order and make specified changes to quantity, items, or pricing.
4. Once changes have been made, re-ship/invoice the sales order.
NOTE: This action is only available for invoices which have not been paid
