This article explains how to purchase an SSL certificate from Managed.com. You will need to generate a CSR (Certificate Signing Request) to complete the steps outlined below. If you haven't already generated a CSR, please see the article How to Generate a CSR
which describes that process.
Now that you have your SSL certificate, you will need to apply it to your site through your Control Panel. SSL Assist
is included for customers purchasing an SSL from Managed.com - please contact support by opening a ticket and attaching your new SSL. If you wish to apply the SSL certificate yourself, instructions for doing so can be found here: How to Apply an SSL Certificate in Plesk