Update a Prefab in the Resources Folder in Edit-Mode by a Script

Hello,

is there a way to Update a Prefab property by a C# Script while I'm in the Editor?

I want to Update/Set the Path of the Prefab as a Script property whtin the Prefab to handle the Resource Loading in the Runtime.

For a few Prefabs it is no Problem to do this by Hand, but if I have a bunch of Prefabs this will take much time and is a souce of errors.

So every Prefab has a Script like:

 using UnityEngine;
 using UnityEngine.Networking;
 using System.Collections;
 
 public class Item : NetItem {
 
     public string path; // this I want so set by a Script
 
     //more variables
 
     void Start()
     {
         // some lines of Code
     }
         
 
 }

The Script sholud only run If I change something in the Prefab or I move it to an other Folder.

Has someone an Idea?