How to Protect a Worksheet in Excel

1. Open the Excel workbook in which you want to convert and replace the date data with day-of-week data. If this workbook is not available, open up a new file for practice. If using a practice workbook, enter some sample data.
2. Select 'Tools' from the main menu.
3. Select 'Protection' from the drop-down list.
4. Select 'Protect Sheet' from the drop-down menu.
5. Left-click with your mouse in the box labeled 'Protect worksheet and contents of locked cells.'
6. Enter a password to unprotect the sheet in the 'Password to unprotect sheet' field. If you do not enter a password, any user will be able to unprotect the sheet and make changes to the data or formulas.