Modifying a prefab

Hi, I want to make a multiplayer game where players can choose their stats and then they would spawn in the world, I made a simple leveling script (it doesn't modify anyt$$anonymous$$ng yet, it simple changes useless values, but later, that values will change the player's stats)

 using UnityEngine;
 using System.Collections;
 
 public class PlayerStats : MonoBehaviour {
 
     public int agility;
     public int health;
     public int strenght;
     public int pointsToSpend;
 
     void Update () {
         agility = Mathf.Clamp(agility, 0, 5);
         health = Mathf.Clamp(health, 0, 5);
         strenght = Mathf.Clamp(strenght,0,5);
 
         pointsToSpend = 9 - agility - health - strenght;
 
         if (Input.GetKeyDown(KeyCode.Y))
             agility--;
         if (Input.GetKeyDown(KeyCode.U) && pointsToSpend  > 0)
             agility++;
         if (Input.GetKeyDown(KeyCode.H))
             health--;
         if (Input.GetKeyDown(KeyCode.J) && pointsToSpend  > 0)
             health++;
         if (Input.GetKeyDown(KeyCode.N))
             strenght--;
         if (Input.GetKeyDown(KeyCode.M) && pointsToSpend  > 0)
             strenght++;
     }
 }

Then I would make a switch statement to choose the values to modify, but how do I modifiy a prefab's values?(T$$anonymous$$s stats would be stored in playerPrefs) T$$anonymous$$s script should be used in the menu, to change the prefab's values, and then when the player wants to he would jump in the world with $$anonymous$$s desired stats