Changing or editing the Cost of Good amount of your sales receipt through your transactions report is just a few clicks away. You can run the said report and then customize it to locate and modify the sales receipt easily.
Go to the Reports menu.
Look for and select the transaction report you want.
Click the Customize button, and then choose the desired Report period.
Go to the Rows/Columns section, and then select Transaction Type from the Group by drop-down.
Navigate through the Filter section, and then choose Sales Receipt from the Transaction Type drop-down list.
Select Run report.
Click the specific amount you'll want to edit, and then make the needed changes.
Choose Save and close when you're ready.
To keep a copy of this report, you can memorize it. This way, you can access it easily for future use.
I'm just a comment away if you have more questions about this. I'll be here to lend a hand.