Homebrew uninstall

You can uninstall Homebrew, the package manager, with following steps:

1. cd `brew --prefix` 
2. rm -rf Cellar 
3. brew prune 
4. rm -rf Library .git .gitignore bin/brew README.md share/man/man1/brew 
5. rm -rf ~/Library/Caches/Homebrew

And you may refer to the FAQ from Homebrew's wiki page.