The first thing to do is fire everyone in the INS who's not a real at the border agent.
The rest of it can all wait, have a moritorium in immigration and visas -- only let in those as tourists from countries where they don't need visa - our allies, basically -- until a new organization can be built from the ground up with a law enforcement viewpoint, not a bleeding heart liberal outlook
Require critical govt agencies to become ISO certified. This kind of crap happens when there is no review or evaluation of customer satisfaction. We are the customer and we are not satisfied by the way the INS is securing our borders.