Deleting a Public Key from a server
Sun Jun 16 00:35:02 2002

When I had a crash (and no backup) I lost my old sec-key. Now I created 
a new one but people don't know which one to use or use the wrong one. 
How can I delete the the old pub-key ?

I am totally new to GPG and Terminal-commands/usage. So please be so 
kind to explain it like to a 3 year old kid. Thanks!