Place all of the Oreos in the package in a gallon freezer bag.  Zip the bag and place on the floor to step on the Oreos to crush.  You could also use a hammer or something heavy to crush the Oreos.

Combine the cream cheese, pudding, and milk in a large bowl with a hand mixer.  Mix until it is smooth with no lumps. Gently fold in the cool whip.

In a 9 x 13 inch casserole dish, begin layering with 1/3 of the pudding mixture.  Sprinkle Oreo crumbles over the pudding evenly.  Repeat this two more times.  Cover and refrigerate for at least two hours.