How to remove 'update-alternatives' links on Linux
I would try cleaning it up manually. I've never done this so make sure you backup beforehand.
- Remove the link from /etc/alternatives
- Remove the relevant file from the admin directory
- /var/lib/dpkg/alternatives/ on ubuntu (debian may be the same but check the man pages under the FILES section)
- /var/lib/alternatives/ on CentOS 6&7