Very easy and very hard. I would put any thing new that you may have done that would show that you are serious. relentless, not giving up, will continue to make yourself better during this process, and are a better candidate now than last year. Good luck.
Yes you should change your personal statement. If schools deemed you unacceptable in your first application, they will want to see some changes in your next application. These changes should be reflected in your personal statement.
have you improved yourself and learned anything from the first cycle? if yes, then i would write about it in your PS. if you have learned nothing, then i would leave your PS alone.
