Welcome to GP!!
A properly used prong collar for controlled walks in low to no traffic areas. A muzzle for vet visits. Start working on a "leave it" command and a "watch me" command. You won't be able to stop the dog from wanting to fight others, as that is what comes with the genetics of bull breeds, but you can teach the dog to focus on you and not on attacking others.
Is the dog truly HA? Or is he just redirecting when he can't reach what he is trying to go after?
Make sure that he is supervised at all times around other dogs, even if he "gets along" with them. Invest in a break stick, learn how to use it, and crate train the dog if he isn't already. Then if crate and rotate becomes necessary, it'll be easier to manage.
Cesar Milan is a band-aid, and spouts false information on a regular basis. It is impossible to train out a genetic trait. And since most bull breeds come from the pit dog, the genetics are there. Seek out a local behaviorist who specializes in bull breeds, one who understands you can't train away genetics. Look into one on one sessions with them until you have the basics down and can work on them yourself.
"i can explain it to you, but i can't understand it for you."