To make a tool I cut off part of a 3/32nd hex key wrench. This allowed me to access the screw that fastens the inside (next to the wing spar) of the 9 pin Sub-D connector. Actually, at one point I considered taking off the roll servo. I should have installed this connector before I riveted on the bottom wing skin. Install the OAT sensor in the middle bottom skin of the right wing. Twist the wires and pull them out to the wing root, leaving enough length for the connectors.
