So far, this is my CSV file, I have skip the headers and also instead of comma separator I added a pipeline separator.

52|12/10/2008|143|MEMBER RECORDS|SIGNATURE CARD|TIF|1|MEMBERRECORDS_SIGNATURECARD_00000000_00000000_000152_001.TIF||70183||01/27/2014|08/15/2001|Document||||MEMBER RECORDS – SIGNATURE CARD|12/10/2008|143|12/10/2008||||KAREN R ADAMS||546790814||
52|12/10/2008|143|MEMBER RECORDS|SIGNATURE CARD|TIF|2|MEMBERRECORDS_SIGNATURECARD_00000000_00000000_000152_002.TIF||70183||01/27/2014|08/15/2001|Document||||MEMBER RECORDS – SIGNATURE CARD|12/10/2008|143|12/10/2008||||KAREN R ADAMS||546790814||
53|12/10/2008|143|MEMBER RECORDS|SIGNATURE CARD|TIF|1|MEMBERRECORDS_SIGNATURECARD_00000000_00000000_000153_001.TIF||712837056||02/02/2012|12/23/2004|Document||||MEMBER RECORDS – SIGNATURE CARD|12/10/2008|143|12/10/2008||||JESSICA P ADKISSON||555657044||
53|12/10/2008|143|MEMBER RECORDS|SIGNATURE CARD|TIF|2|MEMBERRECORDS_SIGNATURECARD_00000000_00000000_000153_002.TIF||712837056||02/02/2012|12/23/2004|Document||||MEMBER RECORDS – SIGNATURE CARD|12/10/2008|143|12/10/2008||||JESSICA P ADKISSON||555657044||
56|12/10/2008|143|MEMBER RECORDS|SIGNATURE CARD|TIF|1|MEMBERRECORDS_SIGNATURECARD_00000000_00000000_000156_001.TIF||423740456|||03/05/1986|Document||||MEMBER RECORDS – SIGNATURE CARD|12/10/2008|143|12/11/2008||||WILLIE MAE ADAMS||423740456||
56|12/10/2008|143|MEMBER RECORDS|SIGNATURE CARD|TIF|2|MEMBERRECORDS_SIGNATURECARD_00000000_00000000_000156_002.TIF||423740456|||03/05/1986|Document||||MEMBER RECORDS – SIGNATURE CARD|12/10/2008|143|12/11/2008||||WILLIE MAE ADAMS||423740456||
56|12/10/2008|143|MEMBER RECORDS|SIGNATURE CARD|TIF|3|MEMBERRECORDS_SIGNATURECARD_00000000_00000000_000156_003.TIF||423740456|||03/05/1986|Document||||MEMBER RECORDS – SIGNATURE CARD|12/10/2008|143|12/11/2008||||WILLIE MAE ADAMS||423740456||

I need to delete “MEMBERRECORDS_SIGNATURECARD_00000000_00000000_0001” on every line/row.

This is my Code:

        private void button2_Click(object sender, EventArgs e)
        {
            try
            {
                if (String.IsNullOrEmpty(FromFile))
                { 
                    lblStatus.Text = "Missing CSV Information";
                    Application.DoEvents();
                    MessageBox.Show("Please select CSV file first.");
                    return;
                }

                if (String.IsNullOrEmpty(ToFile))
                {
                    lblStatus.Text = "Missing Save Information";
                    Application.DoEvents();
                    MessageBox.Show("Please enter save information.");
                    return;
                }
                else if (File.Exists(ToFile))
                {
                    // delete old file
                    File.Delete(ToFile);
                }

                btnProcess.Enabled = false;
                lblStatus.Text = "Processing...";
                Application.DoEvents();

                var lines = File.ReadAllLines(FromFile).Skip(1);
                string docId = "";
                string[] oldLine = null;

                foreach (var line in lines)
                {
                    var newLine = line.Replace(""", "").Replace(".\", "").Split(',');

                    if (docId != newLine[0])
                    {
                        docId = newLine[0];
                        oldLine = newLine;
                    } 
                    else
                    {
                        for (int i = COPY_FROM - 1; i < newLine.Length; i++)
                            newLine[i] = oldLine[i];
                    }

                    using (StreamWriter sr = new StreamWriter(ToFile, true))
                    {
                        sr.WriteLine(string.Join("|", newLine));
                        sr.Flush();
                    }

                }

                btnProcess.Enabled = true;
                lblStatus.Text = "Completed";
                Application.DoEvents();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error! Ex: " + ex.Message);
            }

        }