To access your user settings, click on your user name on the top left corner:
From here you can access different account settings features:
Changing your email
To change your email, go to the Account settings page as described above. That is where you will be able to change your email address and more information. You will be asked to confirm the new email address.
Changing your password
To change your email, go to the Account settings page as described above. There you will be able to change your password.
Switching to Beta
To switch to Beta, navigate to your account settings as described above and then click on 'Switch to Beta' on the top menu.