The login page provides an option directly below the password field to reset your password. 

Once selected, a 'reset password' link will be sent to your email address for action.  If you select the 'reset password' link in the email you will be directed to a webpage that allows you to create and confirm a new password.  To verify the change you will be sent another email to inform you of the change, and with an option to cancel the change in password and to report the change as unauthorised .