There are times when we have to work on a server that is not FreeBSD/Gentoo, and in these unpleasant cases we may even find outdated and broken package systems, in my case it was an Ubuntu Wily where it was impossible to uninstall a package, specifically pmm-admin. This is a small trick to remove conflicting packages on systems like the one described.
We move the package files to /tmp and remove the package using dpkg:
mv /var/lib/dpkg/info/PACKAGE_NAME.* /tmp/
dpkg --remove --force-remove-reinstreq PACKAGE_NAME
dpkg --remove --force-remove-reinstreq PACKAGE_NAME