Install XCode from App Store or DVD.
Download https://s3-ap-southeast-1.amazonaws.com/says-misc/command_line_tools_for_xcode_4.5_os_x_mountain_lion.dmg and install
Open Terminal and run:
curl -L https://gist.github.com/raw/3807116 | bash
rvm gemset use global
gem install bundler
git clone [email protected]:says/says-global.git
cd says-global
bundle install