FOR OWNERS
Simply send your new mobile an new eKey with OWNER permissions.
Once registered your old user entry will be downgraded from Owner to Admin.
It is also advisable to delete the old entry out, just make sure you delete the correct one. The old entry will have ADMIN under the name.
FOR ADMINS
Simply send your self a new ekey, then delete the old one out. Since the user type is the same, you will need to differentiate the name to tell the two entries apart. i.e. John Smith New
FOR USERS
Ask an admin or owner to send you a new eKey for your new mobile.