Once logged in, on the left, you should see information on your orders
Click on the List of orders.
On the screen that comes up, click on the SSL you wish to renew
On the bottom of the screen, there should be a button to "Renew Cert"
CSR Instructions (if needed)
You may need to resubmit the CSR you previously used to purchase the SSL.
A CSR or Certificate Signing request is a block of encrypted text that is generated on the server that the certificate will be used on. It contains information that will be included in your certificate such as your organization name, common name (domain name), locality, and country. You may need to request this from your hosting service.
If your hosting provider can't provide a CSR, you can generate one here: https://csrgenerator.com/. When you generate a CSR this way, you will receive 2 files - a CSR and a Private Key. Keep both for your records.
After the verification process is completed, you should receive your renewed SSL Certificate by email. This cert (along with a private key if you got one) should be given to your hosting provider to install and check. You may also be given a logo to place on your site to verify its security.