Find Specific Child Then Un-Parrent It and add RigidBody For Unequiping items. c#

I'm trying to Create a script that will allow a player to walk up to an item and on pressing a button it will equip the nearest object and put it in the Mountr(right mount) position. If an item is already equipped in that slot then this script below will find child 0 the first child and add a rigid body to it then Un-Parrent it. This is the part im having trouble with, which is adding the rigid body, i keep getting errors like cannot convert transform to gameobject. I don't want to just get this script working i want to learn what im doing wrong and how to avoid this in the future. If you can be detailed in what my mistakes are i would be greatly appreciative.

     public Transform Mountr;
     public Transform Mountl;
     public GameObject Item;
     private GameObject Unequip;
 
 
     void Update () {
         
                     if(Input.GetKeyUp(KeyCode.F)) { //and the player right clicks on me
                 
                 //if(MainHand = true) { // and if this is a main hand weapon
                     
                     GameObject go;    //equip the var weapon in main hand slot
                     go = Instantiate(Item,Mountr.position, Mountr.rotation) as GameObject;
                     go.transform.parent=Mountr;
                       //transform.localPosition = Vector3.zero;
                        //transform.localRotation = Quaternion.identity;
                     //Weapon Weapon = Item.GetComponent<Properties>();
                     //Item = GameObject.Find("Item");
             
                     if( Mountr.transform.childCount > 0 ) {
                         //Destroy( Mountr.transform.GetChild( 0 ).gameObject );
                         Unequip = Mountr.transform.GetChild( 0 );
                         Unequip.gameObject.AddComponent(Rigidbody);
                         //Mountr.Transform.Child.AddComponent( "Mesh Collider" );
                         //Mountr.Transform.Child.AddComponent(Rigidbody);
                         Mountr.transform.GetChild( 0 ).parent = null;
             }
             }

Below is my full script just in case anyone else wants to put something similar in their game and are having problems with some parts of this as well. This script is heavily commented and has a lot of disabled features for the main reason that this is a big work in progress and by far my biggest project thus far. I'm only 2 months into learning unity and scripting.

 using UnityEngine;
 using System.Collections;
 
 public class Weild : MonoBehaviour {
     //public GameObject Weapon;
     //public GameObject Glow;
     //public bool MainHand;
     //public bool OffHand;
     //public int maxDistance = 6;
     public Transform Mountr;
     public Transform Mountl;
     public GameObject Item;
     private GameObject Unequip;
     
     
     void Start () {
          //Player = (GameObject) GameObject.FindWithTag ("Player");
         //GameObject[] Item = GameObject.FindGameObjectsWithTag("Item").Transform;
         //objCamera = (GameObject) GameObject.FindWithTag ("MainCamera");
         //gos = GameObject.FindGameObjectsWithTag(tagName);
         //if (gameObject.tag == "Player") { thisIsPlayer = true; }
     }
     
     
     void Update () {
         
                     if(Input.GetKeyUp(KeyCode.F)) { //and the player right clicks on me
                 
                 //if(MainHand = true) { // and if this is a main hand weapon
                     
                     GameObject go;    //equip the var weapon in main hand slot
                     go = Instantiate(Item,Mountr.position, Mountr.rotation) as GameObject;
                     go.transform.parent=Mountr;
                       //transform.localPosition = Vector3.zero;
                        //transform.localRotation = Quaternion.identity;
                     //Weapon Weapon = Item.GetComponent<Properties>();
                     //Item = GameObject.Find("Item");
             
                     if( Mountr.transform.childCount > 0 ) {
                         //Destroy( Mountr.transform.GetChild( 0 ).gameObject );
                         Unequip = Mountr.transform.GetChild( 0 );
                         Unequip.gameObject.AddComponent(Rigidbody);
                         //Mountr.Transform.Child.AddComponent( "Mesh Collider" );
                         //Mountr.Transform.Child.AddComponent(Rigidbody);
                         Mountr.transform.GetChild( 0 ).parent = null;
             }
             }
 
         
 
                 
         
         
     
     }
     
         
     //public void Wield(Transform parent) {
     
     
         
         //Mountr = get players right weapon mount through 
         //higheriachical call like (/player/body/hand/left_hand/mount");
         
         //Mountl = get players left weapon mount  Or any other means 
         //to select the correct mount of the player who clicks on the item that holds this script.
         
         
         
         //finds all local players
         
         
         
         
         //float distance = Vector3.Distance(Item.transform.position, transform.position);   
         //defines The distance var used in the next line 
                 
         //if (distance < maxDistance) { //if i am close enough to the target
             
             //if(Input.GetKeyUp(KeyCode.F)) { //and the player right clicks on me
                 
                 //if(MainHand = true) { // and if this is a main hand weapon
                     
                     //GameObject go;    //equip the var weapon in main hand slot
                     //go = Instantiate(Item,Mountr.position, Mountr.rotation) as GameObject;
                     //go.transform.parent=transform;
                       //transform.localPosition = Vector3.zero;
                        //transform.localRotation = Quaternion.identity;
                     //Weapon Weapon = Item.GetComponent<Properties>();
                     //Item = GameObject.Find("Item");
             //}
         
                 //else if(OffHand = true) { // otherwise if it is an off hand weapon                                   
         
                     //GameObject go;       //equip the var weapon in offhand slot
                     //go=Instantiate(Weapon,Mountl.position, Mountl.rotation) as GameObject;
                        //transform.localPosition = Vector3.zero;
                     //transform.localRotation = Quaternion.identity;
                     //Weapon Weapon = Item.GetComponent<Properties>();
             
             
         
             //}
         }
     //}
     //}
 //}