At this time it is not possible to transfer core memberships.
You may purchase a core membership in your new account and cancel your current subscription.
Core Membership purchases may be cancelled and refunded if a request is made within 24 hours of initial purchase. If a cancellation request is made outside of the 24-hour window, a purchase cannot be refunded, but it can be cancelled.
If you need assistance with this, please file a Help Desk ticket.