// Create an instance of Workbook class and load the source Excel file Workbook workbook = new Workbook("sample.xlsx"); // Invoke Save method to save as Excel 2003 Spreadsheet XML workbook.Save("Spreadsheet.xml"); // Initialize an object of xmlSaveOptions class to save as plain XML data XmlSaveOptions xmlSaveOptions = new XmlSaveOptions(); // save the XML file by calling the Save method workbook.Save("data.xml", xmlSaveOptions);