What is required to achieve Nirvana in Buddhism? [kītāgirisutta]

Modified from http://www.accesstoinsight.org/tipitaka/mn/mn.070.than.html

"Monks, I do not say that the attainment of gnosis is all at once. Rather, the attainment of gnosis is after respectively training, respectively action, respectively practice. And how is there the attainment of gnosis after respectively training, respectively action, respectively practice?

1. There is the case where, when conviction has arisen, one visits [a teacher].
2. Having visited, one request to be his attendant (see vinaya mahāvagga mahākhandhaka, and CH. III TAKING A MEDITATION SUBJECT of Visuddhimagga)
3. Having been attendant, one listen carefully.
4. Having listened carefully, one hears the Dhamma.
5. Having heard the Dhamma, one memorizes it (dhatā=sutadharo).
6. Having remembered by memorizing, one ponders the meaning of the teachings.
7. Having pondered the meaning, one comes to an agreement through pondering the teachings.
8. There being an agreement through pondering the teachings, wish-to-do arises.
9. When wishing-to-do has arisen, one exerts.
10. When one exerted (an effort), one meditates insight.
11. Having meditated insight, one dedicates his life.
12. Having dedicated his life, one realizes with the mind (discernment's body) the ultimate truth and, having penetrated, enlightened, it with discernment, sees it.

"Now, monks, there hasn't been that conviction, there hasn't been that visiting, there hasn't been that attending ... that listening carefully ... that hearing of the Dhamma ... that memorizing ... that penetration of the meaning of the teachings ... that agreement through pondering the teachings ... that wishing-to-do ... that effort ... that meditating insight ... that dedicating his life. You have lost the way, monks. You have gone the wrong way, monks. How far have you strayed, foolish men (moghapurisa), from this Dhamma & Discipline!