Disintegration

You get the Ground Slam ability during the Jailbreak mission of campaign (second during the second area - Urban). You’ll rescue a bot named Six-Oh-Two that has the ability. Press up on the four way and right bumper to have it use the ability, ideally when it’s near several enemies at once. The ability cool down is over a minute but goes much faster if the bot is resting in the green aura from healing crates.

If you don’t get all of them, you can always replay the mission or you get to use it again two missions later.

As soon as you break out Six oh Two you will need to exit the jail through a grass covered ramp. You will be engaged by a group of club wielding melee bots. Use his ground pound on the as soon as they show up ( with the time slow effect it's easy to line it up just right). It kills them all in one go and nets you 5 kills. Now reload checkpoint and rinse repeat until you got your achievement.