Bolt the completed supply connectors on to the appropriate binding post studs. Try to tuck the wires back as much as possible to avoid hitting the top-mounted fan when the PSU is reassembled. Use zip ties wisely (as if there were any other way).

Grab a prototyping board and solder the resistors down as needed. I'm running a bunch of 2-watt resistors in parallel; remember, wattages stack in this configuration if the resistance values are the same. Mount the board to a free spot on the supply lid and hook up the fancy switch while you're at it.

You did remember to leave an extra 3.3v, 5v, and 12v wire for the resistor board, right?

Hold your breath and power the supply on. When you flip the switch (forgot to mention: this switch ties the green wire to ground...), the LED should light up. If all goes well and you don't see any magic smoke, test the voltages. In my case they were all within 5% or so of the advertised value. Close enough!