You can get an overview of and download-links for the re-motion binaries here:
As explained in the comments, you need an older version
for working with the PhoneBook tutorial.
As for the re-motion sources, you get them from this Subversion
subversion repository: http://re-motion.org/community/Sources/tabid/58/Default.aspx
You can get a Subversion itself here: http://subversion.tigris.org/