Heres an attempt to consolidate the thread into a guide.
If your new to padhacking, highly recommend reading this as it goes over a lot of it http://www.slagcoin.com/joystick/pcb_wiring.html
Before you begin, test the controller out and make sure all the inputs work. Last thing you'd want to do is void it and later discover its a dud.
Start off by removing the boards from inside the pad as done in this vid (you can stop watching at 6:26).
You'll be left with 2 PCBs shown below with the spots you'll be connecting too (optionally you could connect to the pins shown but can be difficult due to close proximity)
On Top Board Topside you'll notice a 'sticker' on the dpad.
You'll want to use something thin and sharp to lift an edge then you should be able to just peel it off.
Gently and carefully scrape off the black stuff at the signal points till you see shiny metal (careful not to scrap too much or you could take off the contact point).
keep going on all the signal points till you have shiny metal visible and ready for tinning.
Tin (apply small amount of solder) the signal points and wires. Can be made easier with the use of flux
Solder the wires to the signal points (put tinned wire against tinned signal point, apply heat and they should join together)
You'll want to apply a dab of hot glue to the wire next to each solder to stop it from moving around and potentially breaking off.
When connecting the triggers (RT & LT), you'll need to use a 100ohm resistor
(img credit MacabreMonster
The two analog cubes can be left on the board or taken off and replaced with resistors.
If leaving on the board simply cut down the grey analog pole that sticks out of the cube and while making sure its centered, apply hot glue to keep it in place.
(img credit socks
If removing, you'll need to replace with 4 resistors (10k ohm recommended).
There'll be 2 sets of 3 points. You'll need to connect a resistor from each of the outer points to the center point.
Once you have everything wired up your ready to add to your stick. The rest depends on what your setup is.
If your just doing an Xbone stick then its just a matter of connecting the wires to the button/stick and feeding a micro usb cable through.
(img credit MacabreMonster
If adding to an existing setup with other boards you'll either want to use a seperate usb cable for xbone and leave the existing usb for your current setup
or you'll need to add a switch to determine where the usb should go (could be an actual switch or an Imp board).
Just make sure every board has power (VCC) and ground connected to it or you'll run into issues with buttons pressing by themselves.