If you forgot your password, just go to the login page. Under the login button, you will find the "forgot your password?" button. Click on it. Type in your email address, and you will receive an email including further guidance to request a new password.
If you only want to change your password, click on your username in the top right hand corner of the platform, and then click on the Pencil Icon ✏️. You will be able to change your password by entering both your old and new passwords.