1. Create a credit for the client that was over paid to bring their balance to $0
  2. Apply the credit to the appropriate invoice
  3. Create the deposit for the new payment
  4. On the payment that was short the over payment amount, reflect the lesser amount (actually paid amount instead of amount of invoice)
  5. Save and close the deposit
  6. Create a credit for the client that was under paid to bring their balance to $0
  7. Apply the credit to the appropriate invoice