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.
Sign up for a new GitHub Enterprise user account.
Add the user to the Owners team for the organization you're transferring.
Sign in (
https://[hostname]/login) 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.