2. Use your expensive wet-etch fabrication system (or order PCBs or whatever) to make the PCB. Make the PCB on halfthickness (32mil) substrate. The final PCB is a .3" diameter circle.
Fuzzy images of the top and bottom. There are three wires coming out: GND (with a black tape around it), LED+ (the other across from gnd), and BATT+ (on the other size).
4. Try to keep the PCB as small as possible, it has to fit in a small space.
7. Now would be a good time to test that the circuit works. Hook up BATT+ and GND to a powersupply, verify that LED+ is at 3.3V. Make a fake load with an extra white luxeon you have kicking around or a 1W 10ohm resistor (or 4 40ohm resistors in parallel, whichever). Verify you still get 3.3V out, you should be sinking ~300mA through the load.
8. Put a piece of doublesided tape on the heatsink to keep from shorting the pcb on the aluminium. Clip the leads and solder them to the LED. Get the polarity right, LED+ is marked with a bit of red glue on the heatsink. LED- is GND is case so dont worry about shorting them together. With a hot iron, solder LED- to the heatsink, in the indentation, so that it doesnt jut out but is a solid connection.
LED+ is protected from touching the heatsink (GND) with a small piece of heatsink, the board sits flush against the heatsink, hopefully will cool the boost converter a little as well as the LED.
9. Carefully reassemble the bulb (test it again?) and solder the bulb bottom back with a big glob of solder. Depending on how much you ground off the heatsink it won't fit together as well as before since the boost is a bit larger than the previous circuit.