You can change several settings for your personal account, including changing your username and deleting your account.
You can change your GitHub Enterprise username at any time.
You can delete your GitHub Enterprise user account at any time. Before you do so, you should hand over the reins of any organizations you might own.
A repository owned by a user account has two permission levels: the repository owner and collaborators.
When you change your GitHub Enterprise username, most references to your repositories under the old username automatically change to the new username. However, some links to your profile won't automatically redirect.
You can convert your user account into an organization. This allows more granular permissions for repositories that belong to the organization.