In my case it was like 15-20 minutes setup, quite easy, but here it is so it can be repeated easilly without issues.

Side-note: there are answered some before-purchase questions regarding SSL certifficate: http://tophostingforum.com/ssl-certifficate-basic-questions-and-answers-4u-t1643.html

1)
Login to WHM (WebHostingManager - if you have cPanel/WHM installed on server)

2) click "Generate an SSL Certificate and Signing Request" in "SSL/TLS" section

3) fill all the fields. As a Copmpany or Organization, i have been told i can enter my full name even im not entrepreneur

4) now you instantly get "Signing Request" code, "Key" code and "Certifficate" code. YOu can save these for future use.

5) in your SSL certifficate manager in your domain registar control panel or in your hosting control panel, activate purchased certifficate. Select webserver type as "Cpanel" or Apache + OpenSSL(in case you dont have cpanel/whm). Now enter "CSR" code you obtained in WHM in step 4. Continue certifficate setup. Confirmation email asking for confirmation will be sent to an mailbox which belongst to the domain that is certifficate setup for.

6) after confirming mail and waiting some minutes or hour you should receive new mail with certifficate code. My email had subject "Your PositiveSSL Certificate for mydomain.com"

-----BEGIN CERTIFICATE-----
***
-----END CERTIFICATE-----

7) then go back to WHM as in the first step of this tutorial and then click in menu "SSL/TLS", then click menu entry "Install an SSL Certificate on a Domain". Enter domain name and then paste your certifficate code you got in step 7 of this tutorial (whole block of code including BEGIN and END CERTIFFICATE)


After i did this, i was able to access my domain with https://
Moreover it appears i did not needed to add new IP for this certifficate, i have one IP and many cpanels on it. And already there are 2 domains, each with its SSL certifficate and both are hosted on same IP.


do you have any ideas regarding this?