I recently found myself having the need to revoke an old certificate. The steps are actually quite straightforward, but you do need to have your old revocation certificate to hand.

For more info, visit the GNU Privacy Guard site: http://www.gnupg.org/gph/en/manual.html

Simple follow these steps. In a terminal, issue:

• gpg –import my-old-key@mydomain.com (0x712AC328) rev.asc
• gpg –keyserver certserver.pgp.com –send-key 712AC328

That’s it!