Inviting collaborators to a personal repository→
You can add users as collaborators to your personal repository.
Removing a collaborator from a personal repository→
When you remove a collaborator from your project, they lose read/write access to your repository. If the repository is private and the person has created a fork, then that fork is also deleted.
Removing yourself from a collaborator's repository→
If you no longer want to be a collaborator on someone else's repository, you can remove yourself.