Demolishers will begin randomly spawning on the map after you face one through the story quests. I found that a demolisher often spawns outside of Atilla's house after it is unlocked as a safe house through a story quest. Next you will want to upgrade your vehicle a bit; however, to do this even faster, unlock the electric cage, flamethrower, and ramming bumper. You can attempt to do some damage to the demolisher before ramming your buggy into it.
Here is a video guide with English commentary for this achievement!
Here is a playlist of guides for this game!
https://www.youtube.com/playlist?list=PL-HeW6XkKdULoe7Za1XPh...