Follow these steps if you have forgotten your password:

1) Go to login page http://www.mynewsdesk.com/user/signin
2) Click on Forgot password? below the green Login button
3) In the next step, insert the email that you registered with
4) An email is sent to your registered address, with a link that you click to create a new password
5) Use your new password to log in on your user account

Please also see:
How to enable and log in with two-factor authentication
What is the difference between a journalist account and a press officer account?