An impossibly easy achievement. I think it may actually be impossible to miss this one as you are promted with the "know how" to smash up those crates, (simply by pressing RB), however a point to note. Some of these green crates can be in places in which when u stomp them, the items decide to start waving cheerfully to you as they begin to hopelessly sink into an endless abyss. Rather than break down into a nervous wreck, simply telekenesis the boxes out of a place that the items can disapear and then smash em up.