To uninstall fex just follow these instructions.
/parrot/jollyroger/non-free///install/index.html web service for transferring very large files users anywhere on the Internet to exchange very large files quickly and conveniently. Parrot 3.7 non-free/web 20160919-1
sudo apt-get remove fex
Which will remove just the fex package itself.
sudo apt-get remove --auto-remove fex
This will remove the fex package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for fex then this will work.
sudo apt-get purge fex
Or similarly, like this fex
sudo apt-get purge --auto-remove fex
|Description||web service for transferring very large files users anywhere on the Internet to exchange very large files quickly and conveniently.|