You can install SSL for a particular domain in cPanel server via WHM.
For that follow the instructions given below,
Login to your WHM.
Select “Web SSL/TLS” icon from the WHM.
Then select “Generate a SSL certificate and Signing request”.
You need to fill all the needed fields here, after that click the create button.
A encrypted version of your CSR and RSA key will be generated and a copy of these will also be sent to the mentioned email address.
Take these two(CSR and RSA) to your SSL vendor to purchase a SSL certificate for you and come back to proceed further.
Select “Install SSL certificate and setup a domain” icon from “Web SSL/TLS”.
Now you need to place the SSL certificate inside the free space and then select Domain name,username and IP address of the particular domain and select “Do it”.
After this the SSL will be installed on the domain.