SAMBA User creation and changing password.

The command is createuser. If you have problems running it you may need to create the directory
/usr/local/samba/private as this is where the user database is stored.

Passwords can be changed using smbpasswd.

You might want to consider running Webmin with the SAMBA module as this simplifies these administration tasks. However it might not be appropriate depending on the function and location of the server.

use

smbpasswd -a user password

to create the user. -a adds the user with the password specified

If you want to change the password just use:

smbpasswd user password