The Minikube tool source code with all the documentation is available at GitHub at https://github.com/kubernetes/minikube.
The following sequences of commands will download the minikube binary, set the executable flag and copy it to the /usr/local/bin folder, which will make it available in the macOS shell:
$ curl -Lo minikube https://storage.googleapis.com/minikube/releases/v0.12.2/minikube-darwin-amd64
$ chmod +x minikube $ sudo mv minikube /usr/local/bin/
Alternatively, if you use Homebrew package manager (available freely at https://brew.sh), which is, by the way, very handy and recommended, you can just install minikube by typing:
$ brew cask install minikube