PrinsValium's method is good. I would recommend using header pins instead of just diode legs. When I soldered the prototype, my Teensy has pins on already. The pins are much big in diameter then diode legs. So when I inserted the pins into the Phantom PCB, it was tight fit and just held the Teensy in place so it was very easy for me to solder it onto the PCB.
I did have to solder on 3 missing pins with diode legs. The diode legs are very thin. So when the solder is melted in the hole the legs act like a straw in a glass of drink, leaning to one side. To get it done, I had to use a pair of pliers to hold the leg, melt the solder, set the leg straight, and let the solder form again. Doing all 31 pins will take some time. And since the legs are thin, when you need to put the Teensy with diode legs onto the Phantom PCB, the Teensy will be loose, shifting its position. You will need some tools or 3 or 4 hands to keep the Teensy and PCB in place and solder them together.
There are so many header pins on digikey, I haven't found the correct one to use yet. :-(