While on the upper level grab the Power Node. Check the lockers around the room for some extra items. After some dialogue with first Ellie, then Nicole, proceed down to the bottom level.
Use stasis and the canisters to deal with the Necromorphs in the room. Make sure all of them are dead before attempting to hack the next door. You'll exchange some harsh words with Tiedemann and he will sic his troop on you. Instead of a straight up fight, leap into the door on the right and make your way through the passage. Remove the batteries to disable the lights. This will summon Necromorphs that will kill off the soldiers for you.
Clear out the Necromorphs that lurk around the hall ways and in the next room. Inside you'll need to repeat the same puzzle from chapter 7: Drag a dead to the doors to lower the security gate. Stock up on items and get ready for another encounter. Take down the Pukers and Exploders before moving onto any surviving Slashers.
Clear out the enemies in the small locker room. There is a locked door, but spending a Node on it isn't really worth it: The room contains healing items, but will also summon a nest of deadly parasites. Continue into the next room and kill off the Stalkers with some stasis and cutter fire. Locate the power cell on the floor and kinesis it to the alcove above. Before exiting grab another Power Node.
You'll arrive at the laser centrifuge. Do not get close to any of the beams or pylons, as the force will be enough to split your torso. Stasis one of the shafts and quickly run around the room to the next alcove. Stop for a second and restock items or kill any Necromorphs that appear. continue this process two more times and you'll reach the centrifuge controls. Shut down the system and lower the bridge. to the next area.
Fight a few enemies that spawn on the bridge before moving into the room. There are a lot of enemies here and little room to wiggly about. Use mines and explosives as much as possible, leaving the Line Gun and Ripper for picking off the survivors. This can be tough, so stick to using powerful area damage. After killing the horde Restock your supplies and continue down below.
A Brute will appear, making it a great time to let loose with your Contact Beam and some handy stasis. Move ahead and talk with Nicole. After a fine conversation, climb into the machine.
For this little mini game you'll need to jam a needle right into your eye. Align the laser so that it shines blue. A red laser will not be aligned correctly and can kill you if trusted too rapidly. Be slow and lower the needle with ease. After stabbing yourself the chapter will end the next will start up right away.