If your AutoSSL option “Allow AutoSSL to replace invalid or expiring non-AutoSSL certificates” is set to on, then it will automatically replace any certificate that is expired within your server. You would not need to follow the steps below as the certificate would be installed. Note that this option is not set by default in order to stop the feature from overriding EV or OV certificate with a DV certificate.

1. Login to the cPanel.
2. Scroll down and click the SSL/TLS icon in the Security section.
   
3. Click the Generate, view, upload, or delete SSL certificates link under Certificates (CRT).
   
4. Scroll down the list until you find the domain that needs to have the certificate installed. Click on the Install link in order to make sure that the certificate is installed.
   
5. In order to see if the certificate has been applied, you can return to the main cPanel page and then click on SSL/TLS Status. Scroll down and you can see if a green padlock is applied to the URL where you installed the certificate.