Purchasing an SSL is a multi Step process. First you need to pick the right SSL for your needs. The Instant SSL is fine for most small businesses but if you are dealing in big numbers or high ticket items your better off with a Pro or Premium SSL. If you need to have multiple Carts that are on different sub domains then you may need a wild card SSL which is quite expensive. You can order more than one Instant SSL's and set them to each sub-domain but if you have many then it reaches a point where the Wild Card SSL would be less costly.
Once you pick out the SSL you need you will need a Signing Certificate! When ordering through our system it emails you a link to submit the Signing Request commonly called a CSR ( Certificate Signing Request ).
For our hosting clients Login into Cpanel and go to SSL/TLS Manager under the Security Section.
There you must first generate a Private Key and then Generate a Certificate Signing Request ( CSR ). The key must be exact as to the domain you wish to use it for. If you submit www.mydomain.com then users will need to use the www for it to work. If it is for a sub-domain then that is the only place the cert will work.
For all others You can get instructions from your Hosting company.
The Request form will have info you must fill in but be sure that this info you type in matches your Domain name Contact info.
If it does not match they will reject it. If the domain contact info is not up to date you must first update it!!
Copy the CSR which you will paste into the Request Form that the link given in your email will take you to.
Fill out the form and here again be careful to be consistent with the info you enter.
Should all go well after you submit the request from you will get an email with the Certificate. You will get three files of which only the one that has your domain name will be used for Cpanel. EX: mydomain.crt Go back to Cpanel and in the SSL/TLS Manager and choose view edit cert. Paste the CRT there and you are done.
Help for system Admins can be found here --> http://www.instantssl.com/ssl-certificate-support/cert_installation/ssl-certificate-index.html
For others you need to refer to your hosting company.