1. Additional buttons were added to the back of the controller by scraping pads on the surfaces of the momentary switches under the A, B, X, and Y buttons.
2. Small wires were soldered to each of the two pads for each button.
3. The other ends of these wires were soldered to the poles of tactile switches with long buttons (bought online at Radioshack).
4. The wires were routed through a small existing hole to the back of the circuit board and held in place, away from the motors, by hot glue.
5. Small holes, just large enough for the tactile buttons were drilled through the back cover on the center side of each trigger, for X and Y, and on either side of the battery pack, for A and B.
6. The tactile switches were mounted through these holes with hot glue.
7. The main board was carefully filed down, avoiding any wire paths, to make room for the tactile switches next to the triggers. Part of the trigger hinges also had to be cut away to make room, but this doesn't end up being a problem because the controller cover holds the triggers in place anyway.
8. Plexiglass was cut, sanded, and painted to make the scuf-style paddles for the back.
9. Two threaded holes were made using a tap to screw the paddles into. On newer 360 controllers, there's a component on the board really close to where one of the screws goes. I ended up having to move the hole.
10. Screw holes were drilled through one end on each paddle.
11. Screws with an appropriate thread for the tapped holes were put through the paddles and screwed into the threaded holes.
12. To keep the paddles from shifting, they were glued to the tactile switches where they made contact using special plastic epoxy. The spots were the switches and paddles made contact were scraped with a razor first to help the glue adhere.
Both the original face buttons and the buttons next to the triggers work and can be used interchangeably. The X and Y buttons next to the triggers can be reached without changing my grip by cocking my wrist slightly. The A and B paddles allow for fluid movement while jumping and crouching. While I still use the face buttons for action games and fighters, I never have to take my thumbs off the sticks for FPS games. Latency issues, due to reaching from one button to another, have become non-existent, allowing me to be competitive in PC FPS sessions using a controller.
The Triggers are adjustable hair triggers purchased from modsticks.com . The scuf-style hair trigger wasn't an option because of the placement of the additional X and Y buttons. Springs can be easily exchanged without taking the controller apart to adjust tension. And, to shorten trigger pull, stoppers can be inserted into one of several trigger bores (this doesn't always work if games make use of analog trigger functions).
The sticks were also purchased from modsticks.com . The right stick has been lengthened, increasing sensitivity and precision. The left stick has been shortened to allow me to change direction of movement faster. Both the left and right sticks have a more slender pole than the original 360 sticks, allowing for greater range of motion and fixing the slow-turn problems inherent to the controller.
The PS3 Grips:
I tried a couple of different methods for attaching PS3 grips to the modsticks because the original modstick grips were metal and uncomfortable. This is what ended up working best:
1. On a broken PS3 controller, both thumbsticks were cut off using a wire cutter.
2. By wedging a dull flat head screwdriver under the edges of the rubber grips they were slowly pried off, being careful not to tear them as they stretched over the plastic disk.
3. The grips were turned inside out and the rubber flanges were sanded off of the insides.
4. The rubber grips were stretched over metal dome grips from modsticks.com by placing the center of the inside-out grip on the center of the metal disk and rolling the rubber rightside-out over the metal dome grips.
The result is a dead ringer for my preferred PS3 thumbstick grips, only a little larger. I've also noticed that the increased surface area of the grips has made rolling my thumbseasier.
While I chose to keep the original, black case. I switched the horrible stock d-pad for a gold bullet pad from modsticks.com and put in some blacked out buttons, leaving the Y button gold for an accent.The bullet-pad isn't the most comfortable, but it looks cool, is super grippy, and you can actually feel it click through all 8 positions as you rotate it, so its a huge improvement over the stock 360 pad.