CHANGE EMAIL ADDRESS
When you load the game, there is a new yellow box just upper the game screen. You can see "Facebook Farm Account linked to:" and your email address. Next to it you will see an UPDATE button.
If the email address is Correct for you, then you don't have to do anything more!
If the email address is NOT Correct then click in UPDATE button, you will see a confirmation message. Click in OK. Then you will get the pop up again to be able to change your email address.