Sagepay - Server

Hi all,
I'm having trouble understanding the instructions sent by Sagepay to integrate Opencart. It's almost like they want me to code??? which i can't do obviously.
I thought it would be simple as the payment method is already part of OC 2.3.0.2
I thought i'd simply take a few bits of info and copy that somewhere on the sagepay account and hey presto all will be well! (just like when i set up Worldpay a couple of years ago)

Am i wrong? Is there a more visual guide?
Thanks

So this was as easy as adding a Vaild IP

Seriously, why make it hard?