Exporting migration data from GitHub.com
To export migration data from a GitHub.com organization, you'll need to use the API to select repositories to migrate. After that, you'll generate a migration archive that you can import into a GitHub Enterprise Server instance.
Preparing the GitHub.com source organization
Before migrating repositories from a GitHub.com organization, ensure that you have the proper authentication and administrative access.
Exporting the GitHub.com organization's repositories
Using the Migrations API, you can export an organization's repositories. After exporting your repositories, you'll download the migration archive that's used for the import process.