To change your AFS password, use: http://afspassword.njit.edu
At some point in the coming months, another command-line program - also named kpasswd - will be made available. This program, however, will be the MIT Kerberos 5 version of kpasswd, and will change the user's Kerberos 5 password. More information will be made available when the Kerberos 5 kpasswd is in place.
Please send any questions on this topic to sys@oak.njit.edu