This achievement can be got in the first chapter but can be a little tricky.
Use the standard X combo to kill a few bambini enemies and increase your mana bar; once it is full press B to grab them and pull off their head.
Now instead of using RS to target an enemy, just throw it using RT at a wall (this is the tricky part as often there are enemies all over the place). Once it is on the floor simply press Y and kick it. You can kick the same head multiple times until it explodes - all of them will count towards the achievement.
There is a second option if this is proving too tricky - towards the end of chapter 1 there is a Witch battle where she will throw bambini heads at you. The idea is to throw them back at her - DON'T, just kick them around using Y.
Good luck