From the Point of Sale interface utilize the Customer button to search and select the customer.

Click on the Trade-In button to bring up the trade in screen.

Fill in the description, set the job tracking, and take any notes you deem necessary.

Fill in the trade in amount then click the Trade For button to add this to the checkout tray.

If the client is also purchasing an item you can add this to the transaction now or even before you started the trade.

Click the Charge button to bring up the payment window and complete the transaction.

When a trade in is processed, a new job will br created in your workshop for the trade in item.  You can either final route the job canceled with a note that this was scrapped OR you can final route the job concluded and receive the trade in item into inventory.  http://docs.bmjapp.help/en/articles/1699271-how-to-receive-stock-from-your-workshop-into-inventory-version-6-1-0