In order to change the email address associated with your Kogan.com account, head to the Contact Details section in your Customer Account:
If you aren't already signed into your Kogan.com account, you will be prompted to do so.
Once you have signed in, you can edit the email address associated with your account by clicking 'Edit' and then changing the email to your intended email address.
Note that this email address must be valid, as you will be sent an email to verify your email address.
It is also important to note that you will not be able to change this to an email address that is linked to an already existing account.