Set Parent EditorScript

This is a snip of my code. I am using Editor script to instance obj into the scene. My objects that I am instancing are to replace objects that are already placed. It grabs their positioning and rotation and scale.

The last thing it is supposed to do is grab the parent of the object its replacing then make itself a child before removing the object in question. Everything works except the parenting. Below is my code. let me know if anyone has had any luck.

My usings using UnityEngine; using UnityEditor; using System.Collections; using System.Collections.Generic;

Script Type : EditorWindow

if (GUILayout.Button ("Set_Tile")) {

                     object[] obj = GameObject.FindGameObjectsWithTag (ChoiceTag);
                     foreach (object o in obj) {
                     
                             GameObject g = (GameObject)o;
                             Transform q = g.transform;
                             Position = g.transform.position;
                             if (DistributeOBJ1) {
                                     n = 1;
                             } else {
                                     n = TH.RN ();
                             }        
                             switch (n) {
                             case 1:
                                     Obj1.transform.position = Position;
                                     Obj1.transform.rotation = g.transform.rotation;
             
                     Choose = Obj1;

                                     break;
                             case 2:
                                     Obj2.transform.position = Position;
                                     Obj2.transform.rotation = g.transform.rotation;
                                     Choose = Obj2;
                                     break;
                             case 3:
                                     Obj3.transform.position = Position;
                                     Obj3.transform.rotation = g.transform.rotation;
                                     Choose = Obj3;
                                     break;
                             case 4:
                                     Obj4.transform.position = Position;
                                     Obj4.transform.rotation = g.transform.rotation;
                                     Choose = Obj4;
                                     break;
                             case 5:
                                     Obj1.transform.position = Position;
                                     Obj1.transform.rotation = g.transform.rotation;
                                     Choose = Obj1;
                                     break;
                             case 6:
                                     Obj2.transform.position = Position;
                                     Obj2.transform.rotation = g.transform.rotation;
                                     Choose = Obj2;
                                     break;
                             case 7:
                                     Obj3.transform.position = Position;
                                     Obj3.transform.rotation = g.transform.rotation;
                                     Choose = Obj3;
                                     break;
                             case 8:
                 
                                     Obj1.transform.position = Position;
                                     Obj1.transform.rotation = g.transform.rotation;
                                     Choose = Obj1;
                                     break;
                             case 9:
                                     Obj1.transform.position = Position;
                                     Obj1.transform.rotation = g.transform.rotation;
                                     Choose = Obj1;
                                     break;
                             case 10:
                                     Obj2.transform.position = Position;
                                     Obj2.transform.rotation = g.transform.rotation;
                                     Choose = Obj2;
                                     break;
                             }
                             
             GameObject clone=null;

             clone=PrefabUtility.InstantiatePrefab (Choose) as GameObject;

             (GameObject)clone.transform.parent=g.transform.parent;
                             
                             //DestroyImmediate (g);
                     }
     
             }

I am trying to have my EditorScript get all tagged items into an array, then set the x,y,z of the