To quit a course on the website, simply locate the course you would like to remove on your Homepage/Dashboard, click the ⋮ icon on the right, click 'Quit course' and confirm your choice.
Alternatively, visit the course's main page, click 'Options' and select ⏹️ Quit.
Please note: removing a course will not delete your progress or learning history. If you want to restart the course from the beginning, you will have to restart it.
To restart a course, simply log in on the website and visit the main page of the course you would like to quit or restart; click 'Options' under your learning progress bar and select 'Restart' from the drop-down menu. All changes will also be reflected in the app (you may have to log out and then in again to see the changes appear).
Both restarting and quitting courses will not erase any of your points.