What are you trying to change?
I'd advise to just create a new ibay rather than changing the primary ibay to suit your needs.
Most Ibay permissions etc are handled by the file smb.conf, located at /etc/samba/smb.conf.
DON'T EDIT that one, rather copy it to /etc/e-smith/templates-custom/etc/smb.conf, as that file gets rebuilt on startup.
cp /etc/samba/smb.conf /etc/e-smith/templates-custom/etc/smb.conf
then edit THAT file.
pico /etc/e-smith/templates-custom/etc/smb.conf
Contol-X to exit, Y to save
Once done, stop samba
/etc/rc.d/init.d/smb stop
expand the template
/sbin/e-smith/expand-template /etc/smb.conf
Restart samba
/etc/rc.d/init.d/smb restart
and if you want to confirm the changes, simply open /etc/samba/smb.conf
pico /etc/samba/smb.conf
or just test your changes manually.