as I'm pretty new to SSL and Zimbra, this might be a stupid question.

My SSL certificate connected to the Zimbra server is not valid anymore. I bought a new certificate and would like to add it.

What do I have to do in order to renew the server's certificate?

In /opt/zimbra/ssl/zimbra/commercial there are four files:
commercial.crt commercial.csr commercial.key commercial_ca.crt

I replaced each file's content with the new certificate. What's the next step? Or did I do anything wrong yet? :-)