This is from my QRH:
1. Cargo Fire Arm Switch (Fwd/Aft as appropriate)...Push
2. Cargo Fire Discharge Switch...Push & Hold 1 Sec
3. Recirculation Fan Switch...Off
4. Right Pack Switch...Off
5. Land Immediately At The Nearest Suitable Aiport.
Notes for items 3 & 4:
This action helps prevent smoke from entering the cabin through the air conditioning system from air that is circulated around and collected in the vicinity of the cargo bays. If the left pack is inop, the right pack should be left on.