The Divert Power Task in Mira HQ consists of 2 stages. The first stage is located in the Reactor Room, all you have to do is flip the highlighted switch, hold and drag it upwards.
The location of the second stage of this task will vary, the rooms that accept the power are: Admin, Cafeteria, Communications, Greenhouse, Laboratory, Launchpad, Medbay and Office. Once you are in the right room, all you have to do is flip the switch in the center.