To uninstall apt-cacher-ng just follow these instructions.
Are you having problems? You can always add apt-cacher-ngagain by following the instructions at this link.
This will remove just the apt-cacher-ng package itself.
This will remove the apt-cacher-ng package and any other dependant packages which are no longer needed.
If you also want to delete your local/config files for apt-cacher-ng then this will work.