Even when your domain is registered with other registrar what matters is who hosts your domain.

To access Cpanel and install SSL certificate is easy. There are two ways:

i)When you have a certificate from other  certificate provider or if you already have the SSL certificate file

• Login to Cpanel using details provided on NEW ACCOUNT INFORMATION
• Go to SSL/TLS Manager on left side panel
• Go to section with certificate and click link below it
• Go to category “install a new certificate”
• Click browse and choose the certificate file (the certificate file must bear .crt)
• Enter the domain name for which the certificate is to be installed
• Click install certificate

1. ii) When you want to generate the certificate and install it

• Login to Cpanel using details provided on NEW ACCOUNT INFORMATION
• Go to SSL/TLS Manager on left side panel
• Go to section with certificate and click link below it
• Go to category “generate a new certificate”
• Under key Select ” generate a new2048 bit key”
• Fill in required details such as domain name, city, state, country, your company name, company division, valid email address, add description as a unique way to identify the certificate
• Click generate button
• You shall receive encoded certificate details and encoded key copy these details separately for storage.
• To install Click return to SSL/TLS Manager
• Go to category “install and manage SSL for your site”
• Click the link” manage SSL sites”
• Select /enter your domain name
• On the certificate space, enter the encoded certificate message you generated earlier
• On the private key space, enter the encoded private key you generated earlier
• Leave the certificate authority bundle blank
• Enable SNI for mail server by ticking on its box
• Click install certificate.