The solution to this problem will vary depending on how quickly you notice the error.
If the incorrect payment has not yet been deposited, then you can simply VOID or DELETE the payment, and then reapply it to the correct Payment Account. The original account balance will be returned to the proper amount and the payment will be eliminated from the current Deposit Batch. Now you can post the payment to the proper Primary Guardian's Payment account.
If the payment HAS been deposited already OR the Accounting Period has been closed then you will not be able to VOID or DELETE the payment. Instead you will need to REVERSE the payment using the Payment Register window.
Go to the Payment Register and select the Primary Guardian who has received the Payment in error.
Find the Payment in the Payment Register and highlight the payment.
Once highlighted, press the REVERSE button
When you reverse the payment from the first account, the charges that were originally covered by the incorrect payment will be reapplied to the guardian's account and the balance will be correct again. However the original payment will still be recorded as deposited. This cannot be changed.
*** Since the newly reapplied payment is not a "real" payment you will probably want to keep it out of the current deposit batch since it will make the true "deposit receipt" balance incorrect. You can keep this reapplied payment in it's own deposit batch with a special note explaining the circumstances of this payment.