What you need and is not included in the explanation in the original post
-Web Certificate Creation Software
-Software that will run a DNS Server on your PC
-The Actual wiring of the router/pc/ps3 and the different ways you need to set it up with regards to the network settings on the lan cards/router/ps3
Truthfully though after reading through this, the "tutorial" isnt very clear at all.
Looking through the cert file there are a total of 36 different certificates and he doesn't state which one we need to replace.
Anyway Back on Topic...
Simple DNS Plus v5.2
Here is a DNS server program with keys that will work to get one started-Software that will run a DNS Server on your PC
use the DNS server to redirect all requests for auth.np.ac.playstation.net to your pc's internal ip
(Learn more about Simple DNS Plus [Only registered and activated users can see links. ])
(Learn how to create a self-signed SSL Certificate [Only registered and activated users can see links. ])