Hi, first of all, you need to have a free dedicated IP for this account. If you have such, assign it to this account. After that, order SSL cert, and as soon as you get it, install in your WHM. You can order SSL through us or using any third-party.
GH provide COMODO SSL certs, if you are interested, please, visit http://glowhost.com/more-products/ssl-certificates/index.php