$ sudo apt-get remove ganglia-monitor 

Uninstall ganglia-monitor including dependent package

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

$ sudo apt-get remove --auto-remove ganglia-monitor 

Use Purging ganglia-monitor

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

$ sudo apt-get purge ganglia-monitor 

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 ganglia-monitor 

See Also,