Open the XLSX file in Microsoft Excel, Google Sheets, or LibreOffice Calc
Click File
Click Save As or Download
Select CSV or CSV UTF-8 as the file format
Choose the destination folder
Save the file
If using Google Sheets, click File, then Download, then Comma-separated values (.csv)
If using Excel, choose CSV UTF-8 if available to preserve special characters
If the workbook has multiple sheets, save each sheet separately as a CSV file
Check the CSV file to confirm the data exported correctly