No, Save As does not overwrite the original unless you use the identical
file name & save to the same folder [in which case you might as well just
Save
]. Save As creates a new file with the name you give it &
incorporates any changes made up to that point. The original file is left
untouched as of the last Save made prior to doing the Save As.
In Mac OS navigate to the file in a Finder window & edit the file name...
Although I believe there are some file management utilities that enable
editing of file names but I've never had need to use any of them.
Regards |:>)
Bob Jones
[MVP] Office:Mac