How to retrieve changed Facebook password
This is really an easy process.
If you have recently changed your Facebook password and you forget it or if some one has changed your Facebook password and you have no access to your account then you can easily retrieved your changed password.
When ever you change a password in your Facebook, you will get an email to the email address associated with your account. The email contains an option to undo the password change. Do it and you will get your account and password back.