This is a straight forward achievement, but in case someone wants a Guide, here you go:
(1) All you need to do are build one of each of the schools mentioned. - (i) Community School (Elementary alternative) is the cheapest of the three. (ii) The Institute of Creative Arts (High School alternative) is the second most expensive. (iii) The Modern Technology Institute (University alternative) is the most expensive of the three.
(2) Place each of (i), (ii) and (iii) above in your city and the achievement will unlock. It is that easy.
(3) Extra point for city builders - Each of the alternative schools use less water and electricity, but costs more, have more upkeep, and less student capacity.
Hopefully this helps. Happy Hunting!