Step 1 Access your WHM account. After logging in, look for the option Install an SSL certificate on a domain name. This can be accomplished by looking up SSL or by scrolling down on the side bar until SSL/TLS is located, below you will find the option Install an SSL certificate on a domain name.
Step 2 In the new window, you will see the boxes Domain, Certificate, Private Key, and Certificate Authority Bundle. Fill in the Domain area with the domain (or subdomain) for which the SSL certificate should be deployed. Paste the certificate for your domain name into the Certificate box. For Comodo certificates, it is a zip file with the name yourdomain.crt that you received when your SSL certificate was issued. Open it in a text editor, such as Notepad, and paste the contents into the box.
The second Private Key box contains the key produced with the CSR you used to activate the certificate on our site. It appears to be a code block with the header ——-BEGIN RSA PRIVATE KEY——. Neither the Certificate Authority nor we have access to your Private Key. If you created a CSR in the same account using WHM, the autofill by certificate button will display once you paste the certificate. Please click on it so that the CA Bundle and RSA Private Key are instantly retrieved. If the Private Key was not automatically retrieved, you must manually enter it into the box. The third Certificate Authority Bundle box is for CA certificates that you normally get along with the certificate for your domain name once it is issued. Comodo sends CA certificates in the form of a zip file. If you have a *.ca-bundle file in your zip, put its contents into the box. CA certificates may also be received in several files; CA certificates varies based on the kind of SSL certificate. Please paste all of your CA certificates into the Certificate Authority Bundle box.
Step 3 After filling in all the fields, click Install certificate
If installed successfully, you should see a message stating that the SSL has been installed successfully and your website should be accessible via https