How to add random with an int

I am doing this lab from Head First C# book
there's 4 dogs and 3 dudes who can bet on those dogs.
dogs will move at random so i have to use random generator.

My question is how do I update the form through the Run() method?


======================Book==========================
class Greyhound {
public int StartingPosition; // Where my PictureBox starts
public int RacetrackLength; // How long the racetrack is
public PictureBox MyPictureBox = null; // My PictureBox object
public int Location = 0; // My Location on the racetrack
public Random Randomizer; // An instance of Random


public bool Run() {
// Move forward either 1, 2, 3 or 4 spaces at random
// Update the position of my PictureBox on the form
// Return true if I won the race
}
public void TakeStartingPosition() {
// Reset my location to the start line











============My Work=========================

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace TheRace
{
    class Greyhound
    {
        public int StartingPosition;
        public int RacetrackLength;
        public PictureBox MyPictureBox = null;
        public int Location = 0;
        public Random Randomizer = new Random();
        


        public bool Run()
        {
            Location = StartingPosition + Randomizer.Next(1,4);

        }

        public void TakeStartingPoisition()
        {

        }

    }