如何将Ruby版本2.0.0更新到Mac OSX Yosemite的最新版本?

I need to update my ruby version from 2.0.0 to the latest version, I can not use some gems because my version is not updated. I had used Homebrew to install Ruby some time ago, How can i update my Ruby version?I need to update my ruby version from 2.0.0 to