It's been done successfully many times in many countries. Look at Britain for example. Say what you will of the problems they have now, but they're undoubtedly better off than when they were under the thumb of the monarchy and the aristocracy. Gradual changes in the law punctuated by occasional serious strides forward led to a near complete abandonment of the previous system.
I'm very skeptical that any group capable of a violent revolution would be effective leaders. The founders were a rare group of brilliant men. The Constitution can be amended, that should be enough.
Supreme Court, Legislative and ultimately voting are all mechanisms that should moderate corruption.
The problem is all of these mechanisms are controlled by the government, which is the source of the corruption. Even voting-- I do believe that the voting machines are corrupted about 50/50- half for democrats and half for republicans. But that only serves to reinforce our one-party-with-two-wings system and exclude greens and libertarians.
I long for the day when all of the nationally televised presidential debates include the Libertarian and Green candidates. (At the 2004 & 2008 elections they put their differences aside and travelled to the debates and tried to get in, and got arrested attempting to do so as a protest of being excluded. And then had a libertarian-green presidential debate. Loved it.)