I went about this the easiest way I could find. I began a game of solo/co-op Conquest and spawned in the large air transport on Orbital. I waited until the enemy were running from their first objective at the launch pad (C1/2) to their second in the middle buildings (B1) and flew across their path, just skimming the ground. You can even land the plane on top of them for the easy kill. I think I may have even clipped a tree coming in and skidded across the ground into an enemy for the kill.
If you're not that great at flying, that may be the best option for you, as long as you don't die until you see the kill register.