Actually no soldering to be done. You take the Fluke apart and replace the keyboard with the Porcupine Electronics LR3 / LR4 interface board, plug a USB cabled into it and you are pretty much good do go.
Here’s a link to Jean-Roberts sensor up in Quebec, as he’s getting snow today.
http://www.jeanrobertmarion.com/sonde2exp.php
Cheers
MikeyM