1. Open the Excel spreadsheet you want to unlock.
2. Select 'Tools,' 'Protection' and 'Unprotect Sheet' from the toolbar. If you used a password to lock the spreadsheet, you'll be prompted to enter it in the 'Unprotect Sheet' pop-up box.
3. Enter the password and press 'OK.' The spreadsheet will unlock.
4. Click on 'File' and 'Save' to save your changes.