This quest will take you to the CIT building in Cambridge (recognizable as MIT in real life) in the northwest corner of Greater Boston. If you haven't learned how to track radio signals in Fallout 4, this quest will show you how. When you reach CIT, select the Courser Signal in your Pip-Boy's radio. The upper left corner of the screen will give you a signal strength percentage based on your proximity to the signal. As you move around, the percentage changes; your goal is to reach 100 percent. If you want a big hint on where to go, head about three blocks east. Your destination is a building called Greentech Genetics.
Expect a great deal of combat as you make your way up the building. You're going to have firefights against Gunners in tight spaces and lots of sentry turrets to take care of. One good rule of thumb is to take cover the moment you step into a new room or hallway as there are a few enemies who'll try to surprise you with rocket propelled explosives if you're within their line of sight. It's a mostly linear path to the top of the building, which is where you'll find your target, Courser Z2-47.
Chatting with the Courser is optional since you're going to fight no matter the conversational choices. Like Kellogg, this boss uses optical camouflage. Again, look for distortions in the background to spot him and follow your companion's line of sight. The area includes a staircase and the room you entered from so you have options for temporary relief spots if you need to mentally regroup and heal. After landing enough shots, the Courser's camo will disappear, making him a much easier target. After you defeat him, loot him for the Courser Chip. The quickest way to leave the building is to reach the rooftop from one of the nearby doors. You can then fast travel from there.