i'm going to answer again, for the sake of acknowledging what anarchists have tried to do, and are trying to do, even though my real answer is still the first one (below).
assuming that by "how can we reach anarchy" you're asking how can a majority (or significant minority) in a given place or perhaps in the world, live in a situation that is recognizable as anarchic by some sizable contingent of people who call themselves anarchists... (keeping in mind that many anarchists don't agree on what that would be)
anarchists have tried propaganda of the deed: which is to incite people through actions (mostly of violence) to act in their own interest (the idea being that once people see that the king can be killed, that the system is not bullet-proof, than we will shrug off our apathy and depression and take up arms for our own lives). that didn't work.
anarchists have tried organizing the workers (and still do, some of them) based on the marxist understanding that the workers are the basis of the functioning of the system, and that once they realize their own power, they can bring the ruling class to its knees (or just bypass it). that hasn't worked.
anarchists have used the turmoil after disasters to show people that we don't need states and bureaucracies to take care of us (a la common ground in louisiana after hurricane katrina). that hasn't worked.
anarchists have published newspapers and journals and books and done radio shows and written plays and drawn comic books to spread the ideas of anarchy (both with and without the label), and that hasn't worked.
anarchists have worked to develop separate infrastructures to take care of people (like local currencies, etc) and to remove the perceived dependency on the state. that hasn't worked.
and anarchists have removed themselves from society to develop themselves and their ideas apart from the eyes and influence of the state, perhaps as a way to prepare for a possible anarchic situation, and that didn't work.
there are probably other ideas. but i'm sad enough now.
edited for typos.