Georgia (the country, not the state in US) reformed the police by firing all cops and hiring brand new ones. Not sure how it will work long term, it was relatively recent.
Back in 2020 amidst the George Floyd murder and subsequent protests, a lot was written about such a program in Camden, NJ: https://www.wbur.org/onpoint/2020/06/11/police-reform-camden.... However I don't know if things are still going well.