Kill the current FBI and replace it with a new Investigative and Counterintelligence Agency.
Most current FBI employees will transfer to the new agency. But transfers would only occur after successful screening. The current FBI staff would go through the equivalent of a “denazification” process wherein the Leftist Agendanistas would be purged and involuntarily separated from federal government employment and not hire by the successor Agency.
The FBI sat on its hands for 50 years while communists infiltrated every Fed agency. They let the DEEP STATE take over.
CTU, and hire Jack bauer to head it up.