$ sudo apt-get remove k4dirstat 

Uninstall k4dirstat including dependent package

If you would like to remove k4dirstat and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove k4dirstat 

Use Purging k4dirstat

If you use with purge options to k4dirstat package all the configuration and dependent packages will be removed.

$ sudo apt-get purge k4dirstat 

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 k4dirstat 

See Also,