Question | Remove text from string

[Sarlula]

I got a string includes text from a .txt file (string s = File.ReadAllText(TextFilePath));

From this string I want to remove all the text that is between the chars "--" and "\r\n".

For example:
Original: "aaaa \r\n -- abcde \r\n aaaa"
New: "aaaa \r\n aaaa"

How can I do it?