1. Click on "Sign in"
2. Enter your info
3. Leave the default settings et continue
4. Fill or skip the small survey
5. Validate your email
6. Go on the main page : https://github.com/neuropsychology/Courses
7. Navigate to the file your want to modify and click on it (or create a new file)
8. Click on the "modify" button (the small pen)
9. Do your changes using the Markdown syntax
10. Preview the changes. Once satisfied, submit your changes (don't forget adding a small description)
11. Create a "pull request"
12. The admins will then see your change proposition and accept it :)