Before we solder any wires, measure the distance from the keyboard socket on the motherboard to the top-right corner of your Macbook. If you want to make it a bit tidier, look at routing your cables between the fan and Bluetooth-card. This area won't have as many cables passing through as it did with the original display location. According to our diagram, the Power Button will be recessed on the top-right, with the USB hub living in the empty Optical Drive bay.
Once you have measured the distance, cut cables to length (stripping an old USB cable is perfect for our cable requirements; thin, flexible and in the correct colours!) and solder them to the top of the pins.
Solder the PWR cable to one leg of a normally-open tactile switch. Solder the other leg to GND. Check the resistance using a Multimeter (should give a reading of "0" when the switch is closed), and then plug the connector into the motherboard. Plug the power or a battery into the Macbook, and then press the tactile switch. If your soldering is good, your Macbook-tablet-mongrel should come to life!
Now switch everything off, disconnect the power, disconnect the keyboard connector and fit the USB D+, D-, 5V pins into the connector. USB GND will be soldered to the GND leg of the tactile switch. This is to avoid unnecessary strain on the connector pin.
The other ends of the USB cables can now be soldered to the USB cable of a small USB hub. I used a four-port hub from Trust, which I stripped and removed three of the ports.
This is so I can have:
-One right-hand side USB port
-An internal bluetooth module (an old Belkin model I had lying around)
-An internal SD card reader (I use this so much on my Macbook Pro that I wish the older Macbooks had one fitted as standard!)
-An internal 3G/HSDPA+ modem (a Huawei E3131, unlocked. Around £15 from eBay)
To see the pinouts, please go to this website: http://pinoutsguide.com/Inputs/apple_macbook_keyboard_pinout.shtml