Unfortunately, the Yubikey NEO I was using for GPG is broken. I have a backup of the private key, but I'm not sure how to import it / configure GPG to not expect the Yubikey anymore. I don't remember exactly how I set it up, but I believe it was this:
https://developers.yubico.com/PGP/Importing_keys.html"After this the keyring is saved, now no longer containing the real secret key, only a pointer that it’s stored on a smartcard."
How can I change that pointer to use the backup of the secret key I have now that I can't use my Yubikey?