I just downloaded the media9.zip package and unzipped it to a subdirectory of C:\texlive. But I don't know where to go from here.
The documentation says: "MiKTeX and TeXLive users should run the package manager for installation", but I don't see anything in the folder tree with names resembling 'package manager' or 'installation'.

media9.zipmanually. – AlexG Jun 15 '15 at 06:42\\in your TeX code (except in tables), you're almost certainly doing it wrong :) – Sean Allred Aug 13 '15 at 16:10