GUI Button to a GUI slider help ?

Hello i'm looking for someone to help me please

The script changes the Values of the stats, skills and vitals but i've used a GUI Button to change the values how can i convert the button into a horizontal slider ?

 using UnityEngine;

using System.Collections; using System;

public class CharacterGenerator : MonoBehaviour { private PlayerCharacter _toon; private const int Starting_Points = 150; private const int Min_Starting_Attribute_Value = 10; private const int Starting_Value = 25; private int pointsLeft;

 private const int offSet = 5;
 private const int Line_Height = 20;
 
 private const int Stat_Label_Width = 100;
 private const int Base_Label_Width = 30;
 private const int Button_Width = 20;
 private const int Button_Height = 20;
 
 
 private int statStartingPos = 40;
 
 public GUIStyle Labels;
 public GUIStyle Name;
 public GUIStyle Buttons1;
 public GUIStyle Buttons2;
 
 
 // Use this for initialization
 void Start () {
     _toon = new PlayerCharacter();
     _toon.Awake();
     
     pointsLeft = Starting_Points;
     
     for(int cnt = 0; cnt < Enum.GetValues(typeof(AttributeName)).Length; cnt++) {
         _toon.GetPrimaryAttribute(cnt).BaseValue = Starting_Value;
         pointsLeft -= (Starting_Value - Min_Starting_Attribute_Value);
     }
     
     _toon.StatUpdate();
 }
 
 // Update is called once per frame
 void Update () {
     
 }
 
 void OnGUI() {
     DisplayName();
     DisplayPointsLeft();
     DisplayAttributes();
     DisplayVitals();
     DisplaySkills();
     
     
 }
 
 private void DisplayName() {
      GUI.Label(new Rect(10, 10, 50, 25), "Name:");    
     _toon.Name = GUI.TextField(new Rect(65, 10, 100, 25), _toon.Name);
 }
 
 private void DisplayAttributes() {
 for(int cnt = 0; cnt < Enum.GetValues(typeof(AttributeName)).Length; cnt++) {
     GUI.Label(new Rect(offSet, statStartingPos + (cnt * Line_Height), Stat_Label_Width, Line_Height ), ((AttributeName)cnt).ToString());
     GUI.Label(new Rect(Stat_Label_Width + offSet , statStartingPos + (cnt * Line_Height), Base_Label_Width, Line_Height), _toon.GetPrimaryAttribute(cnt).AdjustedBaseValue.ToString());
      if(GUI.Button(new Rect(offSet + Stat_Label_Width + Base_Label_Width, statStartingPos + (cnt * Button_Height), Button_Width, Button_Height), "-")) {
         if(_toon.GetPrimaryAttribute(cnt).BaseValue > Min_Starting_Attribute_Value) {
             _toon.GetPrimaryAttribute(cnt).BaseValue--;
             pointsLeft++;
             _toon.StatUpdate();

             

         }
     }
     
     if(GUI.Button(new Rect(offSet + Stat_Label_Width + Base_Label_Width * 2, statStartingPos + (cnt * Button_Height), Button_Width, Button_Height), "+")) {
         if(pointsLeft> 0) {
             _toon.GetPrimaryAttribute(cnt).BaseValue++;
             pointsLeft--;
             _toon.StatUpdate();

             

           }
       }
    }
 }
 
 private void DisplayVitals() {
         for(int cnt = 0; cnt < Enum.GetValues(typeof(VitalName)).Length; cnt++) {
     GUI.Label(new Rect(offSet, statStartingPos + ((cnt + 4) * Line_Height), Stat_Label_Width, Line_Height), ((VitalName)cnt).ToString());
     GUI.Label(new Rect(offSet + Stat_Label_Width, statStartingPos + ((cnt + 4) * Line_Height), Base_Label_Width, Line_Height), _toon.GetVital(cnt).AdjustedBaseValue.ToString());
     }
 }
 
 private void DisplaySkills() {
     for(int cnt = 0; cnt < Enum.GetValues(typeof(SkillName)).Length; cnt++) {
     GUI.Label(new Rect(offSet, statStartingPos + ((cnt + 6) * Line_Height), Stat_Label_Width, Line_Height), ((SkillName)cnt).ToString());
     GUI.Label(new Rect(offSet + Stat_Label_Width, statStartingPos + ((cnt + 6) * Line_Height), Base_Label_Width, Line_Height), _toon.GetSkill(cnt).AdjustedBaseValue.ToString());
     }
 }
 
 private void DisplayPointsLeft() {
     GUI.Label(new Rect(250, 10, 100, 25), "Points Left > " + pointsLeft.ToString());    
     
         }
         
     
 
 

}

Help would be appreciated