After completing the Gearhead Vault job, talk to Redstone to start this one. This will automatically start the Monarch Needed job. Once you have the Monarch, head out into the Wasteland and drive to the Power Plant marked on the mini-map.
When you walk in the Power Plant, the guy sweeping is an enemy. Note: You can shoot the surveillance cameras down and take them Shut of the first electricity switch manually. For the second one you'll need to use electrobolts, and if you don't have any there's some on the floor. Continue to push through, when you get to the path blocked by flame, continue to move slowly as moving forward will trigger new enemies. When you get to the top, flip the switch for the elevator, and defend your position until it comes.
When you get out of the elevator there will be a bunch of enemies waiting just ahead. Continue on and you come to a decapitator room with a flamethrower guy. Wingsticks will make him turn around so you can shoot his backpack or forget to duck the decapitator. Continue pushing through and you'll come to a boss. The pop rocket ammo for the shotgun works great against him. Then pull the switch to get the Power Struggle achievement. On the way out there are two more enemies, then you can start to help Redstone's men by using the different "fatality switches". Then return to Subway Town to finish the job and head down the lift to the Resistance Base to finish the Gaining Influence job and start the Ark Equipment job.