var workbook = new XLWorkbook();
var ws = workbook.Worksheets.Add("Clearing Ranges");
foreach (var ro in Enumerable.Range(1, 10))
{
  foreach (var co in Enumerable.Range(1, 10))
  {
    var cell = ws.Cell(ro, co);
    cell.Value = cell.Address.ToString();
    cell.Style.Alignment.Horizontal = XLAlignmentHorizontalValues.Center;
    cell.Style.Fill.BackgroundColor = XLColor.Turquoise;
    cell.Style.Font.Bold = true;
  }
}

// Clearing a range
ws.Range("B1:C2").Clear();

// Clearing a row in a range
ws.Range("B4:C5").Row(1).Clear();

// Clearing a column in a range
ws.Range("E1:F4").Column(2).Clear();

// Clear an entire row
ws.Row(7).Clear();

// Clear an entire column
ws.Column("H").Clear();

workbook.SaveAs("ClearingRanges.xlsx");