As written a while ago already, password-protected Excel worksheets can be unlocked through a VBA script:
Even simpler is the approach through editing the XML source of the Excel file, as described by paracon.ca/…:
- Rename your file by adding *.zip to its extension.
- Open the zip file.
- Browse to the path ‘xl > worksheets’ folder.
- Extract the protected sheet xml file to local drive.
- Open the xml and delete the markup text <sheetProtection …>.
- Save and close the xml file.
- Overwrite the original xml in the zip folder with the file from local drive.
- Close the zip file and rename the file by removing the .zip extension.