The first part was a crash teaching method, not a method a yet-to-be educated person can do on their own.
The second method just requires free time and an interest in learning the topics of a course. If you can cram an exam with an overnighter, a couple of weeks of spending your free time can get you a better understanding of the same material. All you need for the credential is an opportunity to test past it (not available for many classes, though likely more available as the eliteness of a school increases).
The closest I've ever come to implementing this is reading a bunch in a short time on a topic I find interesting. The one opportunity I had to test past a course I just didn't have the free time, or really the interest, to do so.
The most important thing: Be interested in what you are learning. If you're interested it's not a slog, it's a joy.
