Instructions
Create a class before the match begins that features the claymore as your equipment. The claymore is a motion-triggered trip mine you can set on the map.
Wait for a care package to drop, or earn one yourself with a four-kill streak. Rush to the care package when it drops, so you will be the first one at the location.
Press "Up" on the directional pad to select your claymore.
Set the claymore beside the care package by pressing the "RT" button, and quickly vacate the area. If an opponent comes up to the care package, he should get an unpleasant surprise.