There is an invoice that is already created by our finance, and tax is calculated from AvaTax. What will be the best way to remove the tax from invoice?

issue credit memo, re-create the invoice without tax

Bit new to AvaTax, I would like to remove the tax amount from this invoice itself, as the invoice is still open. So far, I have unchecked the checkbox istaxable at line level, And Under Accounting Tab, Taxitem is set as Avatax. Updated taxrate at 0% Still tax is there, any easier way to remove the tax from existing invoice?

That proposed way will NOT tell Avatax to reduce the amount to NIL!