I found a fairly easy way to get this achievement.
In Episode 3, when you encounter the possessed bulldozer, around 3 or 4 Taken enemies spawn with it. Use your Flashlight or flares to take down their protection, then just run around and lead them into the path of the bulldozer. Once the initial wave of Taken is killed, one enemy will respawn after a few moments. Just light him up, lure him into the bulldozer, and repeat until the achievement pops. Took me about 8-10 minutes.
Before then I probably only got about 2-3 kills through pure luck with environmental causes (like stumbling a Taken off a ledge, or catching one in a Safe Haven light after kickstarting a generator). This is probably the most painless way of getting the achievement, and it's rather satisfying watching a ghost bulldozer mow down possessed loggers/axe murderers.