Of course it is possible! Most Russians for centuries were able to do it. Basically you must live among Russian-speaking people and stop using other languages so sooner or later you will succeed. More or less.
I believe for some people it is possible even without real-life language use. The efforts required are really titanic though because it is a way to cut off most sources and possibilities to learn. If you plan to spend your whole life for solving that problem, you can try.