Simple issue writing from array to text file after storing what I have read as array and editing one of the arrays

Simple issue with writing back from array to text file after storing what I have read as array and editing one of the arrays. I need to write all the information back from the array into the text file.

I have read all the text and they are stored as variable[] called score in Results.

I want to write this back with new scores for one of the players.

I have the players name in a text box on my form

My text file consists of playername, lowscore highscore, blank space line inbetween Then three more players in this format.

                        scores = File.ReadAllLines(Source);
                        int counter = 0;
                        List<Score> Results = new List<Score>();
                        Score scor = new Score();
                        while (counter < scores.Length)
                        {
                            scor.Name = scores[counter];
                            scor.low = scores[counter +1];
                            scor.high = scores[counter + 2];
                            counter += 3;

                        }

                        List<string> NewScores = new List<string>();
                        foreach (Score score in Results)
                        {
                            NewScores.Add(score.Name);
                            NewScores.Add(score.low);
                            NewScores.Add(score.high);
                            NewScores.Add("");

                        }
                        File.WriteAllLines(Source, NewScores.ToArray());