There are various definitions of self-realization, some spiritual and some not.
On a very basic level, self-realization is just that. You become AWARE of who you are.
From a spiritual standpoint, (not necessarily Christian, but spiritual in general,) this would include your beliefs about spirituality- how a "higher power" affects YOUR life. What that "higher power" (God, for example) has in store for your life, what your purpose is on Earth, and the plan that has been put into place for YOU. In addition, it can be thought of "the awakening of your Soul or true 'Self'," according to the Dada Bhagwan Foundation (DBF). I find that definition to be very enlightening.
I would think that the process of self-realization would be a long one, something that could not be attained quickly.