The Airport Express (older than the N model A1264) ready to converted from 110/220 volts to 5 volts. Mark drill position
Large hole - 3 mm deep - marked by tape
Drill horizontally to whe weight of the machine does not provoke an accident
Pull out the plug to the wifi board
Check that it works: Black to ground, orange to 3.3 volt and red to 5 volts
This is hard. Push a thin thread through with screwdriver. Pull a thicker thread back and use it to pull 3 new wires through. Alternatively try with stiff (telephone) wires.
Success! Wires pulled through ready for soldering, isolation and being pushed back inside and covered by a 10 mm plastic plug.
Assemble the parts also used in the hacksaw version of this repair, pack inside the hollowed out plug and close with a hot glue gun. This is easy to disassemble if needed
The 5 volts power plug connected. The 3.3 volt converter gets a bit of fresh air.