// Load PHPExcel library require_once 'PHPExcel/Classes/PHPExcel.php'; // Load Excel file $objPHPExcel = PHPExcel_IOFactory::load('example.xlsx'); // Disconnect worksheets to release memory $objPHPExcel->disconnectWorksheets(); // Change cell value in first worksheet $objPHPExcel->getActiveSheet()->setCellValue('A1', 'Hello World!'); // Save modified file $objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007'); $objWriter->save('modified_example.xlsx');This code loads an Excel file, disconnects worksheets to release memory, changes a cell value in the first worksheet, and saves the modified file. The package library being used is PHPExcel.