A step multiple municipalities have taken in the past is to disband their entire police department and create a new one from scratch, which makes it feasible to eject large numbers of bad actors who would normally protect each other from expulsion while also setting new policies. I don't personally believe that's a complete solution, but it's a logical step and allows you to retain your existing power structures and systems without having to pass a bunch of new laws and create new roles. There are probably many police departments that would not really benefit from this step or merit it.

Another step would be to recognize that you cannot reform american police departments' roles in non-violent crime cases and offload some or all of those entirely to other agencies that don't carry guns. This doesn't fix everything, but it removes many opportunities for things to go wrong while also enabling armed police to focus on the threats that really need them.

See this as an example: https://foreignpolicy.com/2020/06/11/abolish-police-georgia-...