Replaces a gameobject with a prefab

ReplaceGameObjectsWizard.cs

public class ReplaceGameObjectsWizard : ScriptableWizard
{
	private const string PrefsPath = "ReplaceGameObjects.PrefabPath";
	public GameObject Prefab;

	[MenuItem("GameObject/Replace GameObjects",false,0)]
	static void CreateWizard ()
	{
		UnityEngine.Object[] objectsOfTypeAll = Resources.FindObjectsOfTypeAll(typeof(ReplaceGameObjectsWizard));
		if (objectsOfTypeAll.Length == 0)
		{
			var wiz = DisplayWizard<ReplaceGameObjectsWizard>("Replace GameObjects", "Replace");
			if (wiz.Prefab == null)
			{
				wiz.Prefab = AssetDatabase.LoadAssetAtPath<GameObject>(EditorPrefs.GetString(PrefsPath));
			}
		}
	}

	public class TransformValue : IComparable<TransformValue>
	{
		public string Name { get; set; }
		public Transform Parent { get; set; }
		public int SiblingIndex { get; set; }
		public Vector3 Position { get; set; }
		public Quaternion Rotation { get; set; }
		public Vector3 Scale { get; set; }

		public TransformValue(Transform transform)
		{
			Name = transform.name;
			Parent = transform.parent;
			SiblingIndex = transform.GetSiblingIndex();
			Position = transform.localPosition;
			Rotation = transform.localRotation;
			Scale = transform.localScale;
		}

		public void SetValues(Transform transform)
		{
			transform.name = Name;
			transform.SetParent(Parent, false);
			transform.SetSiblingIndex(SiblingIndex);
			transform.localPosition = Position;
			transform.localRotation = Rotation;
			transform.localScale = Scale;
		}

		public int CompareTo(TransformValue other)
		{
			if (ReferenceEquals(this, other))
			{
				return 0;
			}

			if (ReferenceEquals(null, other))
			{
				return 1;
			}

			return SiblingIndex.CompareTo(other.SiblingIndex);
		}
	}

	void OnWizardCreate ()
	{
		EditorPrefs.SetString(PrefsPath, AssetDatabase.GetAssetPath(Prefab));
		
		var replace = Selection.gameObjects;
		var transformValues = new TransformValue[replace.Length];
		for (var index = 0; index < replace.Length; index++)
		{
			GameObject go = replace[index];
			var t = go.transform;
			transformValues[index] = new TransformValue(t);
		}

		Array.Sort(transformValues);

		var newObjs = new GameObject[replace.Length];

		Undo.IncrementCurrentGroup();
		Undo.SetCurrentGroupName("Replace GameObjects with prefabs");
		for (var index = 0; index < transformValues.Length; index++)
		{
			var value = transformValues[index];
			var newObj = PrefabUtility.InstantiatePrefab(Prefab) as GameObject;
			value.SetValues(newObj.transform);
			Undo.RegisterCreatedObjectUndo(newObj, "created prefab");
			newObjs[index] = newObj;
		}

		for (var index = 0; index < replace.Length; index++)
		{
			GameObject go = replace[index];
			Undo.DestroyObjectImmediate(go);
		}

		Selection.objects = newObjs;
	}
}