Much as German "Democracy" fell when the German Democratic Republic was dissolved at the end of the Cold War when the Berlin Wall was brought down. Hopefully Trump will be as quick to dissolve our own Stasi.
I'll dismantle FBI, NSA and CIA. Then I will force everyone who've worked for over 5 years eligible for early retirement. They'll be blacklisted from ever working in the federal government again.
We still have the Marshalls, Secret Service, Border Patrol, etc.
The remaining functions by the FBI will go back to the states. Every state is equipped with their own Bureau of Investigation.