To uninstall task-belarusian-kde-desktop just follow these instructions.
sudo apt-get remove task-belarusian-kde-desktop
This will remove just the task-belarusian-kde-desktop package itself.
sudo apt-get remove --auto-remove task-belarusian-kde-desktop
This will remove the task-belarusian-kde-desktop package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for task-belarusian-kde-desktop then this will work.
sudo apt-get purge task-belarusian-kde-desktop
Or similarly, like this task-belarusian-kde-desktop
sudo apt-get purge --auto-remove task-belarusian-kde-desktop
|Maintainer||Debian Install System Team <email@example.com>|
|Description||Belarusian KDE desktop|