Crackdown

The easiest way to complete this achievement is to earn full strength, agility, and explosives, as well as earn the Firefly and Harlington HMG-90, then go after Los Muertos. And the easiest way to do that is to complete the campaign mode entirely, then reset the gangs.

With full strength, you can take a lot of damage. With full agility, you can get away quickly, as well as get TO enemies easily and quickly. And with full explosives, you can deal out a LOT of damage with ease.

NOTE: Higher level firearms is also a plus, but not as important as the others, and driving skill is even less important. Both can help, but neither is really necessary to worry about for this.

The only case in which having more driving skill is nice would be in case you plan to earn your Roadkill King as well, or if you already have full driving skill and want to take it easy. With the Agency vehicles on 4-Star driving skill, you can easily take out a ton of gang members without breaking a sweat. Just drive around with any of them and plow through gang members as you see 'em. All three vehicles will take 'em out easy as pie (although for gang vehicles, you'll need either the Supercar or the Semi Truck for taking 'em out).

I just got this today and by far the easiest way I found was go into Time Trials, Los Muertos Gang and choose the boss Don Domingo Garcia. You want to pick the Harlington HMG-90, Firefly and Cluster Grenade for equipment. Kill all the enemies and once you get to the boss Garcia don't kill him instead go to the left of where he is and there is two doors where 4 or 5 enemies spawn every few seconds so keep killing them till the achievement pops, it will only take a couple of minutes.

its really simple. just go around taking out lots of groups of gang members, if your shields run out, take cover for a whiile, play defensively and maybe try for some other achivements simultainiously if you dont think you'll die. then after time youll get it. i did this without having 4 stars in anything just look at the order of my achievements. its very simple, trust me.

When going to the Volk main boss on the oil platform, I noticed a door on the first platform where enemies were continually spawning out of. I camped right there, and as soon as they spawned I fired a rocket at them, killing five at a time. Eventually they stopped spawning, and at this point I returned to the nearest supply point (it isn't far away) to restock my rockets. When I retuned to the platform, they were spawning again. I think this method took me maybe 20 minutes or so to complete.