Change Hex value

using System;
using System.Text;
using System.Text.RegularExpressions;
using System.Windows.Forms;
using System.IO;
using System.Diagnostics;

namespace ChangeValue
{
    public partial class FrmMain : Form
    {
        public FrmMain()
        {
            InitializeComponent();
        }
        OpenFileDialog ofd = new OpenFileDialog();

        private void BtnLoad1_Click(object sender, EventArgs e)
        {
            ofd.Filter = "Videos files (*.png *.jpg) | *.png; *.jpg; | All files (*.*) | *.*";
            DialogResult result = ofd.ShowDialog();
            if (result == DialogResult.OK)
            {
                path1.Text = ofd.FileName;
            }
        }

        private void BtnLoad2_Click(object sender, EventArgs e)
        {
            ofd.Filter = "Videos files (*.png *.jpg) | *.png; *.jpg; | All files (*.*) | *.*";
            DialogResult result = ofd.ShowDialog();
            if (result == DialogResult.OK)
            {
                path2.Text = ofd.FileName;
                BtnStart.Enabled = true;
            }
        }

        private void BtnStart_Click(object sender, EventArgs e)
        {
            byte[] image1 = File.ReadAllBytes(path1.Text);
            string hex1 = Bytes2HexString(image1);
            // search the value from hex1
            string copyFromhex1 = "";
            string pattern = @"(?<=\w{60})\w{4}";
            Match match1 = Regex.Match(hex1, pattern);
            if (match1.Success)
            {
                copyFromhex1 = match1.Value;
            }

            byte[] image2 = File.ReadAllBytes(path2.Text);
            string hex2 = Bytes2HexString(image2);
            // search the value from hex2
            pattern = @"(?<=\w{60})\w{4}";
            Match match2 = Regex.Match(hex1, pattern);
            if (match2.Success)
            {
                hex2.Replace(match2.Value,copyFromhex1);
            }

            image2 = HexString2Bytes(hex2);
            File.WriteAllBytes(path2.Text, image2);
            //Process.Start(path2.Text);
            MessageBox.Show("Success");
        }

        private static byte[] HexString2Bytes(string hexString)
        {
            int bytesCount = (hexString.Length) / 2;
            byte[] bytes = new byte[bytesCount];
            for (int x = 0; x < bytesCount; ++x)
            {
                bytes[x] = Convert.ToByte(hexString.Substring(x * 2, 2), 16);
            }

            return bytes;
        }

        private static string Bytes2HexString(byte[] buffer)
        {
            var hex = new StringBuilder(buffer.Length * 2);
            foreach (byte b in buffer)
            {
                hex.AppendFormat("{0:x2}", b);
            }
            return hex.ToString();
        }
    }
}