If the SSL-certificate on your VMware Horizon View Composer server is about to expire, it will have to be replaced. The process is pretty straight forward.
Import the new certificate (in PFX-format) in the Computer certificate store. You can use the MMC snap-in or certutil to accomplish the task. If it's not a publicly signed certificate, you will also need to make sure the intermediate and trusted root CA is imported.
Open an elevated command prompt.
Stop the VMware Horizon Composer service:
net stop svid
Navigate to the install location of View Composer. The default location is C:\Program Files (x86)\VMware\VMware View Composer. On a 32-bit machine, leave out "(x86)".
This will prompt you to select a new certificate by typing in its number and pressing Enter. When multiple certificates are present, check the Subject and Validity dates to confirm you have the right one. If the correct certificate is not visible, you've most likely imported the certificate in the wrong store.
After pressing Enter, the tool will update the configuration (it will say "completed succesfully"), after which you can start the VMware View Composer service again.