You proceed as Desi describes using Bartja's plan with Gregor to do freely as he wishes.
You land the aircars and hike through the woods without encountering any dangers. You approach from the southeast to a clearing where the base has been erected.
In the southeast area is a Sathar vehicle (different from the scout ship) parked on a landing pad.
There are three sets of glass entryways into the building itself on the east side of the building, which you can see leads to a kitchen-like area (south) and a conference room like area (2 north sets of doors).
(Not clear if you brought Appleburg with you. If not, you can show him video remotely, and he confirms this is the place he escaped from. He says that whole eastern area was not really guarded. The area he was held captive was downstairs.)
In the southern rotunda area, you do see video security cameras. Appleburg mentions that he recalls there being a couple of robots patrolling around the building as well.