If your fixed wing is hi-impedance you need one of these:
Bose Fixed Wing Lead
Or if you want a coiled lead one of these:
Bose Fixed Wing Coiled Lead
The lead comes complete with the microphone assembly and you simply undo two screws on the mic, slide the old one out and then slide the new lead in and tighten the screws...........even a fixed wing pilot should be able to do that
FNW