I sell a car, but the buyer wants a different radio. I have stock of that radio and other radios. I replace the radio with a different one but how do I adjust the stock?

Looks like your process is correct, @yamahatci.

In QuickBooks Online, you can adjust the stock using the Inventory Qty Adjustment feature. Here's how:

1. Go to the + New button. 
2. Select Inventory Qty Adjustment.
3. Enter the Adjustment Date.
4. In the Inventory adjustment account drop-down, select the appropriate account.
5. Select the products in the Product field. Note: The description and current quantity on hand auto-populate.
6. For each item, enter either a new quantity or a change in quantity.
7. In the Memo field, enter the details about the adjustment.
8. When you're done, select Save and close.

To ensure you record the inventory properly and you won't experience an error in the future, I suggest consulting your accountant. They help us to keep your data organized and accurate. 
 

I'll share with you these links to help you manage your inventory items in QuickBooks:

• Impacts of inventory tracking on balance sheet and profit & loss reports
• Adjust inventory quantity on hand in QuickBooks Online.

You can always go back here if you have additional concerns. Take care and stay safe, yamahatci.