This achievement requires you to complete all the courses -- 5 in total. Check out the other achievements to find the solutions to specific courses. The video guides in this solution are for the FINAL (course 5) chambers.
Note: I will hunt for some split-screen video solutions. I will update this solution once some are found.
Direct links to the other course solutions:
Course 1 -
The Team Building achievement in Portal 2 worth 12 pointsComplete all test chambers in the Team Building co-op course Course 2 -
Course 3 -
Course 4 -
The Bridge Building achievement in Portal 2 worth 23 pointsComplete all test chambers in the Hard-Light Surfaces co-op course