If the VMCA root certificate expires in the near future, or if you want to replace it for other reasons, you can generate a new root certificate and add it to the VMware Directory Service. You can then generate new machine SSL certificates and solution user certificates using the new root certificate.
Use the vSphere Certificate Manager utility to replace certificates for most cases.
If you need fine-grained control, this scenario gives detailed step-by-step instructions for replacing the complete set of certificates using CLI commands. You can instead replace only individual certificates using the procedure in the corresponding task.