In [My profile] > [Hongkong Post Account] > [Pemit Account], you can choose the permit no from the "My Permit" list on the left, and then click "Dissociate this permit from EC-Ship" in the permit detail section. Finally, click the "Dissociate" button in the confirmation dialog to complete the dissociation.
You cannot cancel the dissociation once the linkage is removed successfully. If you would like to associate the permit account again, please click the "Permit Association" function again.