how to remove the software -- Calibre in Ubuntu

    Today I install Calibre by copying the command from its official website, but what make me crazy is that I can't remove it. I try the command " sudo apt-get remove calibre " and " sudo apt-get --purge calibre ", but they all don't work. I also try to remove it by using  Ubuntu Software, failed.
    Thank goodness, at last, I find the method, using the command " sudo python /usr/bin/calibre-uninstall " and " sudo rm -rf /opt/calibre ".