How to replace public key?

Fri Dec 28 03:51:01 2001


I am looking for the way to replace only my own public key 
without changing private key.
I tried "gpg --delete-key my_own_name", but without removing 
private key, I could not delete my own public key.
Would you please teach me the way if it's possible.

Thank you.

Koji Kishimoto