You need to go into one of the Unlimited buildings at Fort Ithaca. There are two side-by-side; the one you want is on the left. The Imperial guardian is there.
Talk to that dude. IIRC, he will ask you to kill 100 warriors/troopers. After that, he will give you a generic nanobot 0001. Collect enough of the nanobots (10 per armor piece), then exchange a fully repaired piece of vigi armor and the nanobots for the adj version.