Step 1 : In order install SSL certificate for a vanity domain, the respective vanity domain's A record must be pointed to 18.104.22.168(secure).
Step 2 : Once the domain's A record pointing is done, the user have to login to the respective account which holds corresponding vanity domain. In which you can see a install button when you mouse over the domain and can install the certificate.
Step 3 : Once done the SSL unlock icon will be locked. SSL certificate successfully installed.
Note: The above shown vanity domains are just a sample.