To uninstall Huggle, follow these instructions. If you want to remove all of your configuration options, blank Special:Mypage/huggle3.css or Special:Mypage/huggle.css
There should be shortcut to "uninstall Huggle", using that will uninstall Huggle. On Windows, there may be some leftovers in your Program Files (under the folder Huggle) which can also be deleted. Your personal configuration is in AppData/Local/Wikimedia/Huggle and can be also deleted if you want.
Just delete Huggle from your Applications folder. You may also delete your personal configuration that can be found in ~/Library/Application Support/Wikimedia/Huggle.
Debian / UbuntuEdit
You can safely remove Huggle using Package Manager.