Remove configuration files

["Allan Xavier Aguilar Castillo" <pokerom84@gmail.com>]

       ¡Hello there! This is my question: if I wish to eliminate a package plus its configuration files with APT, I just type:

     sudo apt-get remove --purge package

     However, if I have removed packages without eliminate its configuration files (without the command --purge), how can I then eliminate its configuration files, after I have already eliminated the package? Thank you.

-- 
Allan Xavier Aguilar Castillo
pokerom84@gmail.com
GNU is not Unix