- Sign up for a new GitHub user account.
- Have the user's role changed to an owner.
- Sign in to the new user account.
- Transfer each organization repository to the new user account.
- Delete the organization.
- Rename the user to the organization's name.
Article version: GitHub.com
Converting an organization into a user
It's not possible to convert an organization into a personal user account, but you can create a new user account and transfer the organization's repositories to it.