You can change the sales tax setting for an individual item in the "Products" area.
Step 1: Go to the "Products" tab on the top and select "Products" on the left.
Step 2 : Then select the item you wish to edit or add tax on.
Step 3 : Then select the new tax you wish to add on or remove any previous taxes you have already applied to that item by checking or unchecking the box.
*Note: All tax rates must be first edited under "Settings" and then "Taxes"