Displaying ms excel data in DataGridView

public ArrayList ProcessWorkbook(string filePath)
        {
            string file = filePath;

            Excel.Application excel = null;
            Excel.Workbook wkb = null;
            ArrayList al = new ArrayList();
            try
            {
                excel = new Excel.Application();

                wkb = ExcelTools.OpenBook(excel, file, false, true, false);

                Excel.Worksheet sheet = wkb.Sheets["Adresses"] as Excel.Worksheet;

                Excel.Range range = null;

                if (sheet != null)
                    range = sheet.get_Range("A1:X6702", Missing.Value);


                if (range != null)
                {
                    foreach (Excel.Range r in range)
                    {
                        al.Add(r.Text);
                    }
                }
            }
            catch (Exception ex)
            {
                //if you need to handle stuff
                Console.WriteLine(ex.Message);
            }
            finally
            {
                if (wkb != null)
                    ExcelTools.ReleaseRCM(wkb);

                if (excel != null)
                    ExcelTools.ReleaseRCM(excel);
            }
            return al;
        }

//----------------
    public static class ExcelTools
    {
        public static Excel.Workbook OpenBook(Excel.Application excelInstance, string fileName, bool readOnly, bool editable,
        bool updateLinks)
        {
            Excel.Workbook book = excelInstance.Workbooks.Open(
                fileName, updateLinks, readOnly,
                Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
                Type.Missing, editable, Type.Missing, Type.Missing, Type.Missing,
                Type.Missing, Type.Missing);
            return book;
        }

        public static void ReleaseRCM(object o)
        {
            try
            {
                System.Runtime.InteropServices.Marshal.ReleaseComObject(o);
            }
            catch
            {
            }
            finally
            {
                o = null;
            }
        }
    }