If an enemy spots you, you need to move (Oscar Mike = On the Move) and you'll be told to relocate. Do this 100 times.
You can grind this out while playing a solo challenge. Here's how.
On a couple of levels a tiger tank will turn up. Take out every enemy on the map except the tank. "Enemies" should be '1' - just the tank.
Now place a land mine the middle of the road to incapacitate the tank.
This is where the fun starts; run out to the tank so it sees you, when the detection circle turns red start to run away, and you'll see 'Relocate' pop up. keep running away from the point you were spotted until the distance reads 0 M. At this point you will have successfully relocated. Now go back to the spot where the tank saw you and repeat until you get the cheev.
Here's a video I made from the X360 version http://1drv.ms/1ruZZ6E
Note, every once in a while you might get shot at by the tank, so you might need a couple of med kits or bandages.