This is a variant of http://plasmasturm.org/code/vistafonts-installer/ modified to work with Mac OS X.
You need to have cabextract 1.2 or later installed. You can install this with Homebrew or MacPorts.
Run the following commands on the console:
curl -s https://cdn.rawgit.com/atreides322/vistafont-installer/master/vistafonts-installer | bash