Ok so I think I got it with
Code:
$ fetch-ebook-metadata -t "title" -a "author" -o metadata.opf > metadata.opf
$ ebook-meta --from-opf metadata.opf "/path/to/book"
But now I have restarted my server and the new metadata isn't showing up in the book whose metadata I edited. What did I do wrong? The ebook-meta displayed original and changed metadata.