Contact - TUBE FLARING TUBE FLARE ORFS FLARE 37 FLARE 45 FLARE

Within Call of Duty HQ, make sure you're in the Modern Warfare III section and select the Modern Warfare Zombies tile. MWZ is exclusive to MWIII, so you must own MWIII to play. Once you've selected the Modern Warfare Zombies tile, you will have an entire menu of MWZ options to wade through.