There are 12 "Power To The People" Weapon Upgrade stations in all. Their locations are described below.
1. Freezer, Bottom Floor. After fighting Peach Wilkins.
2. Tree Farm. As you first walk under the archway with the giant "Farmer's Market" sign, turn left. The Weapon Upgrade station is on the wall here.
3. In the Worley Winery Basement. At the bottom of the stairs near the U-Invent Station.
4. Southern Mall, Le Marquis D'Epoque. On the lower level, in the area underneath the walkway, near the corpse and audio diary.
5. Poseidon Plaza, Sinclair Spirits on the first floor. Look for a switch on the side of the counter and press it. This switch opens the door behind the falling water. The station is through this door.
6. Hephaestus Core, on the wall across from the Gatherer's Garden station.
7. Kyburz's Office. To the left of Kyburz's desk.
8. Mercury Suites. On the side of the elevator tower opposite the doors.
9. Mercury Suites, Cohen's Quarters. This station can only be used if Sander Cohen is still alive. The door to Sander Cohen's apartment is along the wall to the right of the elevator door. Disturb the two dancers to lure Cohen downstairs. Once he is dead, head up the stairs to his room. The station is on the wall far left of the bed.
10. Fontaine's Center for the Poor, Atlas' Headquarters. Enter Atlas' Headquarters on the fifth floor and take the stairs down to the lower floor. On the wall far to the right of the bloody corpse.
11. Atrium. On the wall behind the Big Daddy corpse that you first see at the beginning of the level.
12. Optimized Eugenics, Eugenic Analysis. At the back of this area, past the Turrets.