$ sudo apt-get remove rt4-fcgi 

Uninstall rt4-fcgi including dependent package

If you would like to remove rt4-fcgi and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove rt4-fcgi 

Use Purging rt4-fcgi

If you use with purge options to rt4-fcgi package all the configuration and dependent packages will be removed.

$ sudo apt-get purge rt4-fcgi 

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 rt4-fcgi 

See Also,