[Zope] Changing the UNIX passwd from zope / python script

Hi all, I needed to be able to change the passwd of a current zope user to sync his passwords with my database. Is this possible ? I could provide an interface and user could confirm the new password and then i could also sync his UNIX password to the same !!! I am a newbie to both zope and python so i would need explicit instructions if there is a solution. thanks bobby