private void Button_Click(object sender, RoutedEventArgs e)
    {
        byte[] byteArray = BitConverter.GetBytes(float.Parse(Tb1.Text, CultureInfo.InvariantCulture.NumberFormat));
        byte[] byteArray2 = BitConverter.GetBytes(float.Parse(Tb2.Text, CultureInfo.InvariantCulture.NumberFormat));
        byte[] byteArray3 = BitConverter.GetBytes(float.Parse(Tb3.Text, CultureInfo.InvariantCulture.NumberFormat));
        byte[] byteArray4 = BitConverter.GetBytes(float.Parse(Tb4.Text, CultureInfo.InvariantCulture.NumberFormat));
        ReplaceData(@"C:Test.bin", 416, byteArray);
        ReplaceData(@"C:Test.bin", 443, byteArray2);
        ReplaceData(@"C:Test.bin", 447, byteArray3);
        ReplaceData(@"C:Test.bin", 474, byteArray4);
    }

    public static void ReplaceData(string filename, int position, byte[] data)
    {
        using (Stream stream = File.Open(filename, FileMode.Open))
        {
            stream.Position = position;
            stream.Write(data, 0, data.Length);
        }
    }

private void Button_Click(object sender, RoutedEventArgs e)
    {
        ReplaceData(@"C:Test.bin", 416, Tb1);
        ReplaceData(@"C:Test.bin", 443, Tb2);
        ReplaceData(@"C:Test.bin", 447, Tb3);
        ReplaceData(@"C:Test.bin", 474, Tb4);
    }

    public static void ReplaceData(string filename, int position, TextBox tb)
    {
        byte[] byteArray = BitConverter.GetBytes(float.Parse(tb.Text, CultureInfo.InvariantCulture.NumberFormat));
        using (Stream stream = File.Open(filename, FileMode.Open))
        {
            stream.Position = position;
            stream.Write(byteArray, 0, byteArray.Length);
        }
    }