How Delete File with Readonly Permission?

    class Program
    {
        static void Main(string[] args)
        {
            string file=@"E:\readme.txt";
            try
            {
                File.SetAttributes(file, FileAttributes.Normal);
                File.Delete(file);
            }
            catch (Exception exp)
            {
                Console.WriteLine(exp.Message);
            }
            Console.ReadLine();
        }
    }