Data is already plural. Even if it were not, you don't use an 's to make something plural.
I have an Excel spreadsheet with multiple worksheets, all with sensitive data. I need to send two of those worksheets to my boss as a new file, but I don't know how.
(You can do a save-as of your original file and delete the other worksheets by right-clicking on the ones you want to delete and choosing "Delete." Or you can create a new file, and, in the spreadsheet you wont to copy, click in the square above the first row and to the left of the first colum, which selects all, press Control+C to copy, and then paste that into your new file.)