Have them navigate to the network drive where the file was located and right click any open area in the explorer window and choose properties Previous Versions.  As you can see it will list several previous versions of the files and folders on that drive.

Usually I have the pick the most recent version.  Keep in mind that any unsaved data entered into the files that was not saved will need to be re entered.  This works very well without having to recreate the files from a backup tape or drive.