Treat him like shit, which he is. Have him understand he's worthless, useless, sitting there on his ass, dreaming his life instead of living his dreams.
Somebody once did that to me. It took a few months to sink deep inside of me, and once it finally made me realize how I was, I went from extreme NEETism to 40k€ job and an expedition in Nepal in three weeks. Since then I haven't stopped, I have a great job, and I keep travelling all around the world to hike and camp in the most remote places on Earth.
Encouraging NEETs is the worst thing to do, it has them believe that what they're doing is enough, that is, maintaining a state of doing nothing but trying to do something without ever succeeding.
You have to push them to their limits to awaken the man inside of them.
