While you are logged out, click the 'Login' button at the top right of any page of the website. Then click the 'Patient Login' link.
On the next screen select the Forgot your password? link.
You then come to the Reset password screen. Enter the email address for your primary user account.
You will be sent an email with further instructions.
The email contains a Reset Password button, click on this.
Enter your primary account email address and the new password you would like to use.
It may be useful to click the little eye icon next to it so you can see what you are typing and avoid any mistakes.
That's it. You're all done. Now you can login using your new password!