What is the best way to reset the course to the beginning?

The Intro to JS programming course my son started last year was a lot of fun.  He didn't finish it and doesn't remember a lot of it.  How can I reset the course to remove all the progress and start from the beginning again? He can go in and watch videos again and all that,but all the assignments and trial programs that he wrote last year are in there.  He wants to start fresh.