How do I correct expenses that were paid from an incorrect bank account?

Hello!  I recently switched checking accounts for a client.  In the interim, we had 2 active checking accounts and several bills were paid from the wrong checking account.  I need to fix this both in QB and in the bank so I can reconcile.  Do I simply edit the transaction and change the "Payment Account" within QB to the correct account?  Or do I need to create a correcting journal entry for each transaction?  Then, do I need to transfer the money for each transaction between the bank accounts or can I do one lump sump transfer when I'm done?  I want to be able to reconcile clean.  Thanks