Soulcatcher is right. Just make sure you heed the advice to "play all the courses" and "complete all your rounds." If you just play SA (especially the front 9) and Kiawah, you will advance to legend before you're ready. Bethpage, especially, helps keep your score more honest.
Having said this, I would strongly encourage waiting until you're around level 60 before attaining Legend status (at least if you weren't "grandfathered in" with better equipment). You simply must have a driver capable of going at least 270 yards to have a prayer from the back tees.