Checks can not be moved from one bank account to a different bank account.

Alternative solution:

1. Void checks
2. Purge the checks
3. Change the bank account on the unpaid invoices to the new bank
4. Re-create the checks, using the original dates from the voided checks

note: This can only be done if your fiscal periods are not Hard Closed. As voiding the payment will make the reversals post back to the period they originally posted.