How do i remove a gpg key from ubuntu apt?

[giraffelife]

apt-key man page: http://bit.ly/2pOtUJN

Ubuntu apt has its own command to manage gpg keys.

$ sudo apt-key list
...
...
...
pub   1024D/D50582E6 2009-02-01
uid                  Kohsuke Kawaguchi <[email protected]>
uid                  [jpeg image of size 3704]
uid                  Kohsuke Kawaguchi <[email protected]>
uid                  Kohsuke Kawaguchi <[email protected]>
uid                  Kohsuke Kawaguchi <[email protected]>
sub   2048g/10AF40FE 2009-02-01
sub   4096R/C2734255 2016-11-01
...
...
...

To remove the key shown. using the keyid.

$ sudo apt-key del 1024D/D50582E6
OK