How do I change the account my product and service item is associated with on the Chart of Accounts

To change which account a Product/Service item is associated with on the Chart of Accounts:

Click the Gear icon > Products and Services.
Click Edit to the far right of the product or service item you want to edit.
From the Income Account drop-down list, select the new account you want for Income account.
If you want all previous use of the item to be changed for non-inventory and service items, select Also update this account in historical transactions. This box becomes available only after the Income Account field is changed. This will not work on Inventory Items. It would not change if you old invoices are associated with the inventory item. You would need to go into your old invoices one at a time, and change to the new inventory item.

If you have already changed the account (missed, Also update this account in historical transactions box) but have not changed the past transactions and want them changed:

Click Gear icon > Products and Services.
Click Edit to the far right of the product or service item you want to edit.
any other Income account (or previous account) from the drop-down list.
Click Save.
Go back and click Edit again.
Change the account back to the correct one.
Select Also update this account in historical transactions. (This box becomes available after the Income Account drop-down is changed.)
Click Save.