Not really sure, but I went around and did a bunch of side-missions, I think I finished 3
or 4 collection sets, a $h!Tload of missions, went to almost 1/2 the planets you can land
on, then got the achievementat citadel station when you either kill saren, or he shoots
him self, as I was talking to him

i no u think im crazy but really if u want a soldier that can use ai hacking just star a
new game with autosave disabled and choose engineer level him up until he can use ai hack
then use it 75 times and dont save just turn off an continue game with old character but
he will have ai hacking skill.