Practically, I guess assume you hold the diode to the pin, solder it, bring the wire to the diode and solder it.
How do you hold the diode, the iron and the solder at the same time?
My guess is you pre tin the switch pin, get a blob of solder on your iron and have the diode in tweezers at the ready then put it all together. It only needs a small bead of solder (and flux).
Right! I can see how it would be fast then. “Just” tin all the pins, and when all the pins are tinned have your solder in a fixed position and then move your iron from solder to pin, stick the diode, and repeat.
Cool!
I soldered on things yesterday doing this, but not tinning the pins first. I fluxed them instead. Then I just picked up solder on the iron tip, used that.
I don't have much experience, so maybe this is too slobby, but for now, things are in place and connected.