The Phantom Tenkeyless PCB is intended for do-it-yourself kits. Mechanical Keyboards Inc cannot be held liable for damage caused by this PCB board; including, but not limited to,
damage from improper installation. Use at your own risk.
Detailed Instructions on Deskthority
(most of the content below from bavman on geekhack.org)
The Phantom PCB is a custom tenkeyless board designed by bpiphany (formally PrinsValium) to be used with the teensy 2 programmable usb controller and a mounting plate.
Compatible / to be used with:

1.5x and 1.25x modifiers
Center stemmed and off-center caps lock
7x Cherry spacebars
ISO and ANSI layouts
5 extra keys above the arrow key cluster
Costar and Cherry stabilizers
6KRO over USB
In-switch LED at caps/scroll lock and Filco style LEDs
Switch top removal without desoldering
LED brightness control
Firmware source code can be used to remap keys


Other Items You'll Need:

TKL Case
Mounting plate
100 Diodes (1N4148)
2 LEDs
2 Resistors for LEDs
2 LED stand-offs for filco-style LEDs
Cherry MX switches
A Teensy 2.0 controller with header pins
Stabilizers (Costar or Cherry)

Tools You'll Need:

Soldering iron
Solder
Wire cutter
Optional: Desoldering tool
Optional: MultiMeter