Okay, it looks a bit brutal in the chart. It isn't. It's the same right hand all the way through. Don't be scared of the "spiders."
Once the roll is solid, this workout becomes something that will build stamina as you get it up to speed. Try different chords with it and see what comes up. I made several quite substantial-sounding pieces with this approach, including the snippet you heard in the introduction, and it's only a silly old banjo roll. That's the point, really—spend a little time on it and a simple banjo roll can lead to all kinds of things way beyond the banjo.