The term key rollover refers to a process whereby one key is systematically replaced by another key in SAML metadata. Since SAML entities (and therefore SAML metadata) are distributed, key rollover must be deliberate, so as not to break the key operations of a relying party.
The general process of rolling over a metadata key in an IdP without causing unnecessary downtime is as follows. The following describes the process in detail for Shibboleth IdPs. The information can be used as inspiration for other IdP implementations.
If you need to replace the SSL/TLS key, you do not need to send anything to Operations. If you have a Apache front-end then you need to create the key, CSR and import the signed certificate into Apache's configuration. If you use Tomcat or another Java container, use keytool and update the server.xml. Restart Apache/Tomcat.