停止
sudo launchctl unload /Library/LaunchDaemons/org.jenkins-ci.plist
起動
sudo launchctl load /Library/LaunchDaemons/org.jenkins-ci.plist
起動したらhttp://localhost:8080/をブラウザで開いて確認
参考 http://damien.co/general/how-to-start-stop-restart-or-reload-jenkins-mac-osx-8022