If you're the only member with owner privileges, give another organization member the owner role. For more information, see "Appointing an organization owner."
Contact the new owner and make sure he or she is able to access the organization's settings.
If you are currently responsible for paying for GitHub in your organization, you'll also need to have the new owner or a billing manager update the organization's payment information. For more information, see "Adding or editing a payment method."
Warning: Removing yourself from the organization does not update the billing information on file for the organization account. The new owner or a billing manager must update the billing information on file to remove your credit card or PayPal information.
Remove yourself from the organization.
Article version: GitHub.com
Transferring organization ownership
To make someone else the owner of an organization account, you must add a new owner, ensure that the billing information is updated, and then remove yourself from the account.