Here are the steps you'll need to take in order to get the achievment.

1.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.Prefer "Kasserine Pass" level since we need to take down tiger tank in the end.

2.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.

3.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 achivement.

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.