This article provides information on how to replace certificates using H5C UI in vCenter server 7.0 Update 3 and later.
There will be an alarm in the vSphere UI:
STS Signing Certificates are about to expire
This error is due to the STS certificate for the vCenter Service Appliance (VCSA) is nearing the expiration date.
Follow the steps below to Update the STS signing certificate using vSphere client UI.
Note: Before making any changes, please create offline (cold) snapshots of all the vCenter servers in the environment.
In an Enhanced Linked Mode (ELM) setup, this should be performed on a single vCenter, and a restart of all systems in the SSO domain is required afterward.