Problem removing a public key whose private key is gone

[Jeremiah Foster]

Hello,

I overwrote the partition upon which my private key was stored. To
confuse matters I generated a new secret / public key pair on the same
machine and even imported my old public key, thinking, rather foolishly,
that I might somehow be able to restore the destroyed secret key.

How do I properly remove the old, unusable public key when I do not
possess the secret key any longer and without destroying my entire gpg
installation.

Kind regards,

Jeremiah