[gX:~] # /usr/local/etc/rc.d/samba stop

[gX:~] # cat /etc/rc.conf
…
nmbd_enable="NO"
smbd_enable="NO"
winbindd_enable="YES"
…

[gX:~] # cd /usr/local/etc/

root@gX:~# /etc/init.d/samba stop

root@gX:~# apt-get install winbind

root@gX:~# cd /etc/samba

gX# cat smb.conf 

[global]
        workgroup = ADX
        security = DOMAIN
        idmap uid = 20000-40000
        idmap gid = 20000-40000
        template homedir = /home/%U
        template shell = /bin/sh
        winbind cache time = 36
        winbind use default domain = Yes
        winbind enum users = yes
        winbind enum groups = yes

gX# testparm 
Load smb config files from /usr/local/etc/smb.conf
Loaded services file OK.
Server role: ROLE_DOMAIN_MEMBER
Press enter to see a dump of your service definitions