How to move a key to a retired slot on Yubikey PIV?

Question

I need to generate a new key pair for signing on Yubikey but I would like to "backup" old key. The yubico-piv-tool documentation mentions slots 82-95 for Retired Key Management, which seems to be for that purpose. But I cannot see any action which would allow moving or copying keys between slots. How can I move/copy a key from slot 9c to one of the retired keys slots with yubico-piv-tool or other tool?

Elayneelazaro