Are you using the 31 release or prerelease? The mode was changed to experimental right before release. Just FYI, I think the comment you replied to is by the a

Are you using the 31 release or prerelease? The mode was changed to experimental right before release. Just FYI, I think the comment you replied to is by the author of the mode and an upstream Emacs contributor, so I would assume their instructions are up to date for the 31 release.