On level 2 the restrooms are near the inner computer lab (or right side when entering from the tower stairwell), with the men's room being slightly down the hall.
On level 3 the restrooms are located directly opposite the Reference desk, in the alcove. These restrooms are gender-neutral.
On level 4 the restrooms are located on the Eastside as on the second level, with the women's near the Quiet Room, and the Men's just up the hall towards the Tech Service desk. It is around a corner in a short hallway.