Use the environment against an enemy.
During one of the fights with the Hunter you'll notice a pillar in the middle of the area. If you do a combo (a simple 3 hit combo) while the pillar is behind the Hunter you'll start a button mashing mini-game. If you win this you'll throw him into this pillar and you'll get the achievement.
There are several pillars like this throughout the game, they are found in the center of the room in most boss battles.