My Uber driver was an actor from London. In London he used to play in Shakespeare and Gilbert & Sullivan shows, though he has a bit more trouble here. Apparently he is told that Americans won't understand his English accent. <sigh>
Anyway, he did get a part in a play where he'll need an American accent. I asked him how he will do that, and he has hired a consultant. He said that it is hard to change your own accent because you just don't hear the differences. Have you ever changed your accent? Or read anything about people who have?
PS He also promised me he'd join Wordcraft. We'll see...