If I were President, I would fire each and every ATF special agent on day one (1). They are the bottom of the barrel for federal law enforcement anyways. I would go further that any current and former ATF agent would never be allowed to work for ANY .gov, ever.
I would allow some exemptions such as the explosive division, which, IMHO, is the best in the world on arson and explosives, which would be moved to the FBI. However, if they ever worked with the NFA Branch or anything to do with firearms...buh bye.
I'd go a little further: I would put all government agents on notice that all prior violations of people's civil rights would be prosecuted if they were unlawful at the time they were committed, regardless of whether the agents expected anyone to care. I would allow agents a deal: with certain exceptions, they could be moved to the bottom of the priority list for prosecution provided they signed and notarized agreements indicating that if they ever worked in any position where they would have discretionary authority over a private citizen, or over a government agent who did have such authority, they would wave any statute of limitations relative to their crimes. Much as I'd like to see most of the crooks in government rot in prison, just getting them out of government would be 99% better than leaving them in.