At the site you have the option of either changing or resetting your password.  Here is the difference.

You change your password when you KNOW your current password.

You reset your password when you DON'T KNOW your current password, but HAVE created a password profile.

If you haven't created a password profile, and don't know your current password, you can contact IT by emailing or calling 617-349-8770, and pressing option 2.