How do you get the mongoose mowdown achivment?

easy but not so easy you have to splatter someone in a ranked playlist(lone wolves,squad battle;etc online) with a mongoose and then you get the scout shoulder pieces i got it on lone wolves but i recommend doin it in squad battle with a friend or a shooter on the back. its harder than it sounds.you get the scout head by getting the used carsalesman achievement destroy a vehicle with three people in it such as a prowler in campaign. you get the body by getting the too close to the sun achievement in campaign or online again i recommend having a friend guard you in squad battle and what you have to do is destroy a banshee with a spartan laser or a missle pod.