using( var workbook = Workbook.Load( "test.xlsx" ) )



  {

    // Get the first worksheet. A workbook contains at least 1 worksheet.

    var worksheet = workbook.Worksheets[ 0 ];

        

    // AutoFit the rows "I" to "P", from 6th and going right, and make sure the row's heights are between 0 and 409.



    worksheet.Rows[ "I","P" ].AutoFit( 0, 255, 5);



    // Save workbook to disk.

    workbook.Save();

  }