Jerry Seinfeld gives a good example of how to change your mind in public, here: Jerry Seinfeld says he was ‘wrong’ to blame ‘extreme left’ for killing comedy.
Not only does he says his old way of thinking was wrong, but he shows that he has considered what he thought before and contrasts that with his new way of thinking.
If you have to change your position on a topic in public, it’s not enough to say, “well I thought A before, but now I think B”. You want to show why you no longer think that way. It shows you’re thoughtful and sincere.
No one likes having to change your mind in public. If you have to do so, consider the way Seinfeld did it.