Teaching two thousand people would be a pain. Although Leon could ask for a payment, he decided to make them work to protect and rebuild the city. Before anything, he decided to divide those two thousand into four groups. Each group would work for six hours protecting the boundaries of the city or working inside to make things more convenient. After that, Leon would teach them for two hours.
Leon had a hard time organizing those people, but since they would help the city, he didn't have to do it alone. Everyone helped him, at least everyone who was living in Amanda's house. Amanda, Hector, Betty, Sasha, and even Gisela helped.
Some individuals complained when they learned that they had to work in order to live in Las Vegas and to learn magic, and so they left. But the majority decided to help; they became even eager to help after the first day of lessons. Leon managed to make every single of those two thousand survivors use Earth Manipulation.