Team Xecuter has released complete details on how to read and write the Xbox One NAND. Full credits go to Tydye81, Juvenal, RF1911 and RickyB82.
For the 2 x GND wires use 12 awg For the other use 28 awg
2 = CMD
3 = GND
5 = CLK
6 = GND
7 = DATA
1. Enable SMC_RESET (VERY IMPORTANT YOU DO THIS FIRST)
Place a 200-300 Ohm resistor between J4E1.1 and TP4E1
2. Disconnect the SMC Clock from the Southbridge by removing R4D2. Save the resistor as it is needed for your Xbox One to function. If you lose it then a solder bridge should work as the value is 0 Ohms.
3. NAND logic runs on the 1.8v rail and readers try to use 3.3v which is why most of them don't work with the Xbox One NAND.
Bridge an 700-800 Ohm resistor between Pin 1 of U3C3 and Ground. This should make the output 3.3v on the rail without damaging anything because the smc is held in reset so it won't try to power anything on.
4. Directly underneath the NAND on the bottom side of the motherboard are access points that will let you easily solder the CMD, DAT0 and CLK lines.
Everything works better when you hook everything up to the SD reader with everything turned off, then turn the Xbox on and then plug in the SD reader.