O'Bryan could have equally said is "...all it would take is designing, manufacturing and qualifying a probe, together with the structural changes to the aircraft, writing and qualifying the new software and repeating all the nessasary clearance trials done to date."
It would be just as accurate but would give a better impression of the task. We live in an F-35 world where the small opening to allow the gun to fire can upset the aircraft enough for the gun to miss and the gun installation was part of the A design from the beginning. Slapping on a probe and going for it is probably not a viable option.