The basis of the state is class struggle, so to eliminate it you eliminate class. The basis of class is differences in relation to the means of production, so the answer is to collectivize all production. Until we get there, classes will remain, thus elements like police are necessary to keep the proletariat in control and capitalists oppressed, and as production and distribution collectivizes then so too will the basis of the state itself become unnecessary as class struggle fades alongside class itself.

It isn’t by magic, it’s based in sound analysis of socialism and the economic basis of class and the state itself.