Inside the Warden’s Office, you will see a room on the right side that has an electrified door. The part will be inside here, but to get it, you will need to shock three electrical panels that are in the Generator Room, down beside the docks. In the large room between the Docks and the Citadel, there will be a bunch of electrical panels, the same type you shocked to lower the Warden’s Key. You will need to shock the three panels that are lit up. There will be two in the Generator Room and then a third that will be through a portal at the far end of the room to hit as well.
Once the three panels are hit, you will then need to return to your body and return to the Warden’s Office to enter the small office and grab the part off the table. To open the Warden’s Office, you will need to basically do the same thing as when you get the Warden’s Key from spot 2, except you will need to go to the right when you float through the portal and find the volt machine there to shock which will then open the Warden’s Office door, allowing you access to the now accessible part.