The revocation of a certificate is an emergency procedure that allows invalidating a certificate. Once your certificate has been revoked, you can't request that it be recreated for free.
We suggest that you use the procedure only if you don't want to use this certificate anymore.
To revoke your certificate, go to the SSL certificate list in your Gandi account, and click on the “X” icon that you see to the right of the certificate in question.
Remember that if you lost the key and would like to generate a new one, you should not revoke the SSL but regenerate the key from your SSL panel management :