win32net.NetUserChangePassword
NetUserChangePassword(server, username, oldPassword, newPassword)
Changes the password for a user.
Parameters
server : string/PyUnicode
The name of the server, or None.username : string/PyUnicode
The user name, or None for the current username.oldPassword : string/PyUnicode
The old passwordnewPassword : string/PyUnicode
The new passwordComments
A server or domain can be configured to require that a
user log on to change the password on a user account.
If that is the case, you need administrator or account operator access
to change the password for another user acount.
If logging on is not required, you can change the password for
any user account, so long as you know the current password.
Win32 API References
Search for NetUserChangePassword at msdn, google or google groups.