On this page of the Marvel's Spider-Man Miles Morales guide, you will read about the fifth main mission called La Nochebuena.
Rewards: 3500 XP
The marker will lead you to Miles' home. Approach the backpack on the roof of the building and press the triangle. The hero will change back into his normal clothes and enter his room through the window. You can explore it for a while. Scan the surroundings and look for objects to interact with, and then go to the living room. After a short cutscene, Miles' mother will ask him for help in Christmas Eve preparations.
Walk around the living room and kitchen. You can, for example, look inside the fridge, talk to your mom or Ganke. Light the Christmas tree and go to the turntable to turn on the music. Rio will ask Miles to bring the records from her bedroom.
In Rio's bedroom, you will find a file about the mysterious Prowler on the floor. Then, select one of the three available records and return to the living room. Go to the turntable and insert the vinyl. When the doorbell rings, go to the door to let Phin in.
After a short conversation, a power outage will occur. Go to the circuit breaker in the hallway and press the triangle. You will have to go out the window of your room and find a transformer on the building outside. Use R3 to scan your surroundings. You are not wearing your Spider-Man suit so nobody should see you. Follow the wall to the left, walk around the building, do not get up to the roof and avoid windows to remain unnoticed.
Follow the marker until you find the transformer. Get closer and follow the instructions on the screen. When the power in the entire building is back on, return to the apartment through the window in the living room to complete the mission.