can't undo bank reconcilliation

Hi

I have followed all your steps and when I go to Reports - bank recon - select bank account nothing comes up.

See below how can I fix this as I have two account that have been allocated incorrectly and need to be changed but it comes up  

This transaction has been reconciled.

1-0020 cheque account           1-0040 saving account           1-0060 Undeposited funds