How to unlock .xlsx file?

This excel file I can’t expand, can’t modify, how to unlock it?
Thanks.

menu:File>Save as… somewhere in your documents directory.

not working.
“Protected cells can not be modified.”

Try

  • clicking Tools > Protect sheet, if the sheet wasn’t saved with a password then that will remove the protection.
  • Selecting everything on the sheet (Ctrl+A) and copying to a new spreadsheet

no password, not working.

What exactly do you do?
What exactly happens?

I have tested with only Excel 2010 password protected sheet and password protected workbook. In that Ctrl+A then copy and paste to a new spreadsheet always pastes unprotected data. I suppose newer Excel versions will have stronger security so you must ask for the password(s)