Removing gpg keys

gpg keys can normally be removed from the /etc/apt/trusted.gpg.d directory.

This would be in the format of sudo rm ...

However if the keys are stored in /etc/apt/trusted.gpg then we need to use;

sudo apt-key del [keyid] which is fine for older? systems where the following shows a list of the keys;

sudo apt-key list

and the keyid field would be shown but on modern systems that seems not to be the case, so this time, we again use sudo apt-key list but note the last 8 characters of the long number and this becomes the keyid which can then be removed by using;

sudo apt-key del [keyid]