$ sudo apt-get remove mkvtoolnix 

Uninstall mkvtoolnix including dependent package

If you would like to remove mkvtoolnix and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove mkvtoolnix 

Use Purging mkvtoolnix

If you use with purge options to mkvtoolnix package all the configuration and dependent packages will be removed.

$ sudo apt-get purge mkvtoolnix 

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 mkvtoolnix 

See Also,