How do you remove sharing from an Excel file?
I am not aware of any sharing access for individual Excel files
(if someone reading this knows how to do this with Windows, please
improve the answer). File sharing permissions are for giving access
to folders, not individual files. If you are not able to change the
sharing permissions on the folder in which you have the Excel file
stored, move the file to a folder or drive without sharing
permissions.
See related questions and links for information about file and
folder sharing.