About changing the default branch
You can choose the default branch for a repository. The default branch is the base branch for pull requests and code commits. For more information about the default branch, see "About branches."
Note: If you use the Git-Subversion bridge, changing the default branch will affect your trunk branch contents and the HEAD you see when you list references for the remote repository. For more information, see "Support for Subversion clients" and git-ls-remote in the Git documentation.
You can also rename the default branch. For more information, see "Renaming a branch."
Si tienes permisos administrativos en un repositorio, puedes cambiar la rama predeterminada para que sea otra rama existente. Para obtener más información, consulta la sección "Configurar la rama predeterminada".
Prerequisites
To change the default branch, your repository must have more than one branch. For more information, see "Creating and deleting branches within your repository."
Changing the default branch
- En GitHub, visita la página principal del repositorio.
- Debajo de tu nombre de repositorio, da clic en Configuración.

- En el menú izquierdo, da clic en Ramas.

- Under "Default branch", to the right of the default branch name, click .

- Use the drop-down, then click a branch name.

- Click Update.

- Read the warning, then click I understand, update the default branch.

