Which mod did you have in mind? The FCC mods were "Plug-n-Play" electrically, IIRC. IJ's Ü2NXT is mechanics only, but the matching Hall Effect sensors from CubPilot required only inserting the appropriate wires into a bit on the HE-sensor's cables and press the bit together to make the contact permanent. (Splicing? Kinda like what you do with network cable and plugs)
I've found that the hardest part of modding a Cougar was the disassembly of the stick. The small nuts covered with that red glue are a pain to remove. The second hardest part is replacing a spring. That's far less of a chore and more a requirement of measured and consistent strength.
If you have a technical friend, he could give you a hand for pizza and a beer.