No, it's rarely time to do something that drastic. We had PM Mulroney who wisely separated the spy agency from the RCMP and created CSIS, but that is because the RCMP had run amok, Burning barns, entrapping (they still happily engage in entrapment, as do the Toronto and Ontario police, a function of a centralized, socialist system that wants "order" and not "law") and using agent provocateurs.
As it were, CSIS ended up being almost as bad, in fact, we had dirty RCMP agents just quit the intel from the former agency and get hired by CSIS. Bloody joke.
Ultimately, it's going to take some honest, very loyal current and former FBI agents to speak out and support cleaning bad apples and high ranking Obama leftovers. I am sometimes blindly loyal to history, and the FBI are definitely one of the best, and outside of the few bad years with J Edgar Hoover (against a very dangerous and real threat from the Communists which created the hysteria), the FBI have been very good.
This situation is going to have an impact, but one should not jerk the knee and assume the entire agency is bad, it's absolutely not. They still keep Americans and others fairly safe, especially considering how man foreign enemies America has from China, Russia and even allies.