The ownership of a group belongs to the account the organizer used to create the group. Groups cannot be separated from the organizer's account.
When you can no longer manage your group and wish to transfer the group ownership to a third party, you will also need to transfer your account ownership. You can do so by changing the email address of your account. Do note that, by changing account and group ownership, you will disclose all your account history and information (including ticket purchase history) to the person who is taking over your account.
If you do not wish to disclose your account information, we recommend the new group owner to create a new account and group. In this case, groups followers from the old group will not be transferred to the new group.
If you wish to add co-organizer to your group to manage the group together, please see Managing events with multiple users: adding co-organizers for more information.