$ sudo apt-get remove fvwm-icons 

Uninstall fvwm-icons including dependent package

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

$ sudo apt-get remove --auto-remove fvwm-icons 

Use Purging fvwm-icons

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

$ sudo apt-get purge fvwm-icons 

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 fvwm-icons 

See Also,