Open the Excel workbook
Go to the worksheet tab (bottom)
Right-click the sheet tab
Select Unprotect Sheet
Enter the password (if prompted)
Click OK
If the sheet is protected at the workbook level: go to Review → Unprotect Workbook
Enter the workbook password (if prompted)
Click OK
If the sheet is protected for specific actions: go to Review → Protect Sheet and confirm protection is removed (password may be required)