There are two ways you can go about this. One, be a beast and don't die (Which will never happen for me Lol) or two, put on assassin pro, blind eye, dead silence, grab a sniper rifle (so you have a guille suit), some silenced secondaries, get 1 kill with 0 deaths and go hide in a corner of the map in a hardcore lobby (no radar). I did this on MW1. I have tried it on MW3 but only wound up dying in the end. Cheap tactic I know, but unless your a beast player (which I am not) it's the only way I know of how to even attempt it. Just make sure that when you try it you have the challenge unlocked, that way it's not a waste of time. Lol.