I think it's rather hard to get a bigoted person to see the targets of their hatred and prejudice as being fully human and deserving of empathy and equality. I certainly tried with my ex-family and ex-friends from my hometown across the years. But what you can do is increase the social consequences for bigotry and shame and shun them into silence. I don't think we will ever be able to get people like this to relinquish their stubborn cruelty but we can make them afraid to express that cruelty