You quickly put on the armor. It's actually very uncomfortable; quite painful in some areas. But it fits. You grab four grenades, a rifle, and a pistol. You climb back up into the ceiling. It's harder with the armor, but still possible with enough effort. Once back inside the maintenance area, you crawl back towards the security room.
You remove a panel and check to see if the guards are still there. Yep - one manning the consoles and one guarding the exterior. After quietly removing just enough panels for you to jump down, you silently drop from the ceiling. You take out your pistol. You're actually unsure on how it works - you know that Occupier weaponry is energy-based, but have no idea how it works beyond that. You assumed the items in the armory-like room you were just in was ammunition, but you're not sure. You took a few "magazines" just in case, though.
The pistol does seem simple enough. You aim and shoot at the person manning the console. They get hit in the chest and collapse onto the surface of the console, slumped in their chair. The other guard immediately notices and spins around, firing multiple shots into the wall behind you. But you manage to get the better of him with a burst of energy blasts in his general direction, a few hitting him and knocking him to the ground.
You look at your pistol again - a small display reads the familiarly unfamiliar Occupier language. From what you've seen, you think it's numbers. You put the pistol away and arm a trap. You place a grenade next to each console and your last one hidden on the inside of the doorframe. You put together a tripwire that should detonate the grenades, effectively destroying the room and its occupants. Hearing a party of soldiers draw near, you depart into the corridors away from the security room.
You hear an explosion in the distance as you quietly run away. You lean against a wall for support as you regain your breath and consider your next moves. You think you're close to the various hangars. You hear yells and footsteps in the background, consistently getting louder as you can only assume they near your position. What now?