Adding a magnifiying glass to cocos2d

[Shades of Chaos]

This has already been asked at
iphone - Add a magnifier in cocos2d games - Stack Overflow
But I didn't quite understand the answer. I am using the same tutorial Let's Spot It is using but I'm not sure where to put madhu's code. I also don't know what the runAction method looks like. Could someone please explain to me how to do it, or tell me if there is another way to accomplish a magnifying glass in cocos2d.

Thanks

Clinton Walsh