manually remove homebrew (if for some reason https://raw.githubusercontent.com/Homebrew/install/master/uninstall fails)

homebrew_remove_man.sh

#!/bin/sh
# Just copy and paste the lines below (all at once, it won't work line by line!)
# MAKE SURE YOU ARE HAPPY WITH WHAT IT DOES FIRST! THERE IS NO WARRANTY!

function abort {
  echo "$1"
  exit 1
}
set -e
/usr/bin/which -s git || abort "brew install git first!"
test -d /usr/local/.git || abort "brew update first!"
cd `brew --prefix`
git checkout master
git ls-files -z | pbcopy
rm -rf /usr/local/Cellar
bin/brew prune
pbpaste | xargs -0 rm
rm -r Library/Homebrew Library/Aliases Library/Formula Library/Contributions
test -d Library/LinkedKegs && rm -r Library/LinkedKegs
rmdir -p bin Library share/man/man1 2> /dev/null
rm -rf ~/Library/Caches/Homebrew
rm -rf ~/Library/Logs/Homebrew
rm -rf /Library/Caches/Homebrew
rm -rf /usr/local/.git