To manage certificates in vCenter, follow these steps:
1. Log in to vCenter using the vSphere Client.
1. Go to the Administration menu and select the vCenter Server option.
1. Under the Configuration tab, select the Certificate Management option.
1. Click the Replace Certificate button.
1. Choose whether you want to replace the default certificate with one you have created, or with a certificate from a certificate authority (CA).
1. If you choose to use a certificate from a CA, enter the certificate information and click the Replace button.
1. If you are replacing the certificate with one you have created, browse to the location of your certificate and key file, enter the passphrase if required, and click Replace.
1. Review the certificate information and click OK.
1. Restart the vCenter Server service for the changes to take effect.
1. You can also manage certificates for individual ESXi hosts by selecting the Hosts and Clusters option in the vSphere Client, and then selecting a host. Under the Configure tab, select the Security Profile option, and then click the Edit button in the Certificates section to replace or update the certificate for that host.
