Only do this on files you own. Using this on employer or client files without permission violates the Computer Fraud and Abuse Act (CFAA) in the US and similar laws globally.
: A script that extracts the Excel file, strips the sheetProtection tags, and re-zips it. Excel Password Remover Github
You might wonder, "Why not just buy PassFab or iSeePassword?" Here is why the GitHub ecosystem dominates this niche: Only do this on files you own