Thanks, I have the same slow startup issue with oh-my-zsh. But the link does not talk about how to migrate from oh-my-zsh to prezto. Which files should I copy

Thanks, I have the same slow startup issue with oh-my-zsh. But the link does not talk about how to migrate from oh-my-zsh to prezto. Which files should I copy over, or compare and update once I install prezto ?