My godfather just sent me an email saying that he has a spreadsheet at work that he or any of his colleagues know the password for. Does anyone know anything that can remove/reset the password on Excel spreadsheets?

I found this:
http://www.straxx.com/excel/password.html
Excel Help: Excel Password Recovery and Removal

Haven't used any of the recommendations myself.

Used this and work.
Advanced Office XP Password Recovery

Password Recovery Software

While I haven't used them myself, I know several people who have successfully used their tools.