Step 1 - From the account creation/login page, click 'Need help signing in?' and Forgot Password.
Step 2 - Enter your email that you used to create your NAF account. It is most likely your school email. Then click Reset via Email.
You'll receive an email with your instructions for the next step, open that email (it may be in your spam folder) and click the blue Reset Password button.
Step 3 - Enter your security question answer. Then you will be prompted to set a new password.