Unity / XCode / AdMob

Good afternoon gentlemen!

I am a broken man, I have been trying to get AdMob integrated into my IOS game for the past 5 days with no luck so far. Let me tell you what I have so far...

I have built the game in unity. I have opened the file in XCode.

I am following this guide for Unity 3 here :http://forum.unity3d.com/threads/174131-How-To-Add-AdMob-Ads-Into-Your-Existing-Unity3D-iOS-%28iPhone-iPad-iPod%29-Game?p=1191339#post1191339

Now i Understand I am using Unity 4, but I can't find any tutorials out there for 4.

I have gotten up to the part "- STEP ONE DONE"

And I am now onto the coding part, which I am guessing won't work as I am using Unity 4.

So i scrolled down to see the comment regarding unity 4, I am struggling to understand what he means, can anyone give me a step by step guide of what code needs to go where?

I would greatly appreciate it,

Regards, A Broken Man :(