Removing collaborator permissions from a person contributing to a repository
- 
On GitHub, navigate to the main page of the repository. 
- 
Under your repository name, click Settings. If you cannot see the "Settings" tab, select the dropdown menu, then click Settings.  
- 
In the "Access" section of the sidebar, click Collaborators & teams. 
- 
To the right of the collaborator you want to remove, click Remove. 
Next steps
- For reference information, see Permission levels for a personal account repository.