We are currently working on upgrades to Buyer Group list management features in Seller Admin, so until those new controls are ready for primetime, self-service list management is currently unavailable.
If you need to add/remove/change an email on any of your Buyer Group lists, we can do that manually for you; please send your E-junkie account password, or your original activation code would suffice if you still have your original "Account information" email from us, along with your request:
https://www.e-junkie.com/ej/contact.php