A few months ago, my laptop suffered a filesystem crash and I had to perform a complete re-install. I had back-ups. No big deal. However, while I was in Australia, the back-up of my GPG key was on an inaccessible system in Scotland, resulting in me having to generate a new keypair.
Now I’m home and have access to all my files again, and seeing as (almost) everyone is using my new public key anyway, I thought I’d be as well cutting down the confusion and properly revoking the old one.
This is simple enough provided you know your passphrase or generated a revocation certificate before you forgot it! In my case, I issued the following commands:
$ gpg --output revoke.asc --gen-revoke 1A27C8BB
$ gpg --import revoke.asc
$ gpg --keyserver pgp.mit.edu --send-keys 1A27C8BB
Easy.