If the purchase order status is Open, and the receipt has not been posted, and an invoice has not been created from the receipt, you can edit the values.
1. In Accounts Payable Records, open the Purchase Order and select the Receipts tab.
2. Open the receipt, and open the receipt line. 3. From the menu bar, select Receipt, Go To. If Invoice is an active choice, click Invoice. 4. Delete the invoice. 5. Save and close all records, and reopen. 6. Edit the receipt.