public static void Main()
var hex = "7B5C727466315C616465666C616E67313032355C616E73695C";
var rtfBytes = FromHex(hex);
var rtfText = Encoding.ASCII.GetString(rtfBytes);
Console.WriteLine(rtfText);
public static byte[] FromHex(string hex)
var result = new byte[hex.Length / 2];
for (var i = 0; i < result.Length; i++)
result[i] = Convert.ToByte(hex.Substring(i * 2, 2), 16);