get the children

child.cs

foreach (Transform child in transform) {
    child.parent = null;
    child.collider2D.isTrigger = false;
    child.rigidbody2D.isKinematic = false;
    child.rigidbody2D.AddTorque(Random.Range(-torquePower, torquePower));
    child.rigidbody2D.AddForce(new Vector2(Random.Range(-.5f, .5f), 1.0f) * forcePower);
}