How to change the name of workgroup for Windows (SAMBA)

The workgroup item under AD SUPPORT item, and followng steps for your reference:

OS5:

ADMIN WEB UI->USER AND GROUP AUTHENTICATION->ADS SUPPORT->WORK GROUP/DOMAIN NAME-> modify to your own group name->APPLY.

OS6: (N45x0 & N43x0 supported, N25x0 & N2310 available around 2014 Q4)

Click left upper corner gear box->CONTROL PANEL->FILE SHARING/PRIVILEGE->ADS SUPPORT->WORK GROUP/DOMAIN NAME-> modify to your own group name->APPLY.