If you forgot your user account password and need to reset it, there are several places on the site to request a password reset.
From the main login page:
At the bottom of the login page is a forgot password section. Click on the link in this section to reset your password. You will be prompted to enter your username and will receive an automated system email to your email address on file. This email will contain a password reset link that will allow you to setup a new password.
From the My menu:
If you are already logged into the site with the generic account, you can click on the Having trouble logging in" link from the My menu in the header. This action will open the same forgot password prompt and allow you to send yourself a password reset link.
From the page tools:
If you are already logged into the site with the generic account, you can click on the "Having trouble logging in" link inside any page tool, located on the search results or view pages. Add To and Custom Segment are two examples of where this is possible.