In pretty much the same way that to get oil you just drill a hole in the ground and then pump it out.
The second page in this thread has a post of the general run down of building one of these things, and you'll also find on several occasions I've posted no desire to make a full blown tutorial because of all of the different controller versions that can be used. This includes walking someone thru a build step by step by step by step as well because it's not really a beginner type of controller build.
You should use a Wired CL for the 'base board' because it's by far the easiest to trace out and see what goes where to rewire the Common Line of it into the PS3 controllers 3 COM line setup, and wiring the Sticks up is just a straight shot back to the PS3 controller's board.
Easier, but costs more, depending on how much the CL controller cost you, would be using the 36X board I designed awhile back for your 'base board' so there's no ruining a 360 board to use. http://forums.xbox-scene.com/index.php?sho...w=&st=&
The absolute easiest I can make it for you is to just build it for you, which comes with 2 things, a PS360 controller that works, and a lightening of your wallet. Which compared to the cost of the minimum of 2 controllers most people kill attempting this, plus the time/parts spent on it, plus the aggravation, you'd find it a lot better deal, but that's really only understood after the fact in most cases.