brew install stephan-hesselmann-by/BlueYonder/<formula>
Or brew tap stephan-hesselmann-by/BlueYonder and then brew install <formula>.
Or install via URL (which will not receive updates):
brew install https://raw.githubusercontent.com/stephan-hesselmann-by/homebrew-BlueYonder/master/Formula/<formula>.rbbrew help, man brew or check Homebrew's documentation.