Как изменять значения переменных извне

private string serv = "C:\\server\\";
private string regserver = "C:\\server\\login";
private string getfile = "C:\\server\\soft\\";

private string getserv = "C:\\server\\";
private string serv = "D:\\server\\";
private string regserver = "D:\\server\\login";

 if (!File.Exists("cfg.ini"))
{
FileInfo fi = new FileInfo("cfg.ini");
fi.Create();
}
else
{
StreamWriter sw = new StreamWriter("cfg.ini");
sw.WriteLine("Путь до сервера");
sw.WriteLine("---------------");
sw.WriteLine(getserv);
sw.WriteLine("---------------");
sw.WriteLine(serv);
sw.WriteLine("---------------");
sw.WriteLine(regserver);
sw.WriteLine("---------------");
sw.Close();
}

StreamReader sr = new StreamReader("cfg.ini");
            Console.WriteLine(sr.ReadToEnd());
            Console.ReadLine();

var config = MyProjectNamespace.Properties.Settings.Default;
config.serv = "C:\\server\\";
config.regserver = "C:\\server\\login";
config.getfile = "C:\\server\\soft\\";
 
config.Save();