public GameObject Child;
Child.transform.parent.gameObject.SetActive(false);
gameObject.transform.parent = null // Remove parent of Game Object
transform.parent = null;
Destroy(transform.parent.gameObject);
transform.SetParent(parentTransform, true);
transform.SetParent(null, true);
transform.SetParent(parentTransform, true);
transform.SetParent(null, true);