In the desktop Excel app, you might use VBA or password recovery tools. But and limited recovery options. So how do you desproteger (unprotect) the sheet?
You open an Excel file in Microsoft Excel Online (the free browser version), try to edit a cell, and get the error: "The cell or chart you're trying to change is on a protected sheet." desproteger excel online
How to "Desproteger Excel Online" – A Practical Guide (When You Don’t Have the Password) In the desktop Excel app, you might use