I modified a document file and accidentally saved it as a spreadsheet file. How do I save the odified file as a document?
From the menu File → Save As (or File → Save for new files)
In the save dialog which opens there is a drop down for file type.
There you can select to save the contents of the active sheet as a CSV file, (a text type file)
With that selected click save and another dialog will open which allows you to set the options for that data export to CSV format.