Click on "Forgot your password" on the login page to create a new password. You will then receive an email with a link to create a new password for your user account.
For more information about the status of your subscription, please have a look at the settings page. Here you can extend the term of your subscription and upgrade.
You can change the email address of your user account under Settings in the login area. Please note that your username will be changed to your new email address.
You can cancel your Premium subscription any time online under Settings. With the cancellation the automatic renewal is switched off, but you can still use all Premium features until the expiry date.