What
Install Homebrew into a local directory when you don't have sudo access.
Why
The default Homebrew installer writes to /usr/local and needs admin rights. Cloning the brew repo into your home folder and adding eval "$(brew shellenv)" to your shell gives you the same package manager without touching system paths.
How
# Clone Homebrew
git clone https://github.com/Homebrew/brew homebrew
# Add to PATH
eval "$(homebrew/bin/brew shellenv)"
# Initialize
brew update --force --quiet
chmod -R go-w "$(brew --prefix)/share/zsh"