You can uninstall or removes an installed dlang-libevent package itself from Ubuntu 16.10 (Yakkety Yak) through the terminal,
$ sudo apt-get remove dlang-libevent
If you would like to remove dlang-libevent and it's dependent packages which are no longer needed from Ubuntu,
$ sudo apt-get remove --auto-remove dlang-libevent
If you use with purge options to dlang-libevent package all the configuration and dependent packages will be removed.
$ sudo apt-get purge dlang-libevent
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 dlang-libevent