You can uninstall or removes an installed chocolate-heretic package itself from Ubuntu 16.04 LTS (Xenial Xerus) through the terminal,
$ sudo apt-get remove chocolate-heretic
If you would like to remove chocolate-heretic and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove chocolate-heretic
If you use with purge options to chocolate-heretic package all the configuration and dependent packages will be removed.
$ sudo apt-get purge chocolate-heretic
If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.
$ sudo apt-get purge --auto-remove chocolate-heretic