Move invoice/payment amount to new site

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We have a group of suppliers set up with one site that is tax reportable and and one site that is not tax reportable.  Some of the invoices/payments that should have been on the tax reporting site were incorrectly created and paid on the site that is not tax reportable.  How do we go about moving the dollar amount to the tax reporting site so the amounts are correctly reflected on 1099s?

I am assuming we would need to create a credit memo on the non tax reporting site for the amount of the invoice, but I'm not entirely sure where to go from there.