How to delete systemd units?

[Palooka]

Hi,

I have a couple of units which evidently have failed:

[palooka@f15 ~]$ systemctl list-units --all --no-pager|grep error
ip6tables.service         error  inactive dead          ip6tables.service
livesys-late.service      error  inactive dead          livesys-late.service
[palooka@f15 ~]$ 

ip6tables is not installed, and livesys-late is, I know, a remnant of having installed from a Live CD.
So as far as I can see, all I need do is to "remove" these somehow from systemd's purview.

How do I go about doing that, please?

Thanks,
Palooka