-Enter the hole in the washroom (2)

Enter room 301 on your right and get the SUPERINTENDENT'S KEY from the left orange photo in the back room. The LOCKER KEY #106 is on the other photo but isn't needed.

In the back room, find JOSEPH'S ARTICLE by the superintendent's key.

In the living room, find MIKE'S DIARY.

If you have the RED PAPER, you can collect another memo in your apartment later.

If you have the RED PAPER, place it under 302's door in the hall.

Enter the stairway, ignoring the Man with the Coat and his SHABBY DOLL, and head all the way down to the west wing at the bottom left.

Enter apartment 105 with the SUPERINTENDENT'S KEY and get the APARTMENT KEYS on the living room wall. You can use these keys to open any apartment from this point.

If you want two more memos later, you will need the RED PAPER and TORN RED PAPER near the keys.

In 105's bedroom, find the SUPERINTENDENT'S DIARY (UMBILICAL CORD).

Exit room 105, cross over to the east wing, and enter apartment 102.

Kill the Tremers in the kitchen and open the fridge to get the TORN RED PAPER from inside. This is the only red paper required here.

Eileen's SUBMACHINE GUN will be on the counter here if it's unlocked.

If you don't care about memos or other unnecessary items, you can skip ahead to 302's front door.

Inside 203 in the east 2F wing, find another TORN RED PAPER in the shirt in the northwest bedroom, which you'll need for another memo.

The BUG SPRAY is on the living room floor in 203.

RICHARD'S REVOLVER and a PUTTER are found in 207's living room and back room.

Return to the third floor and place all pieces of RED PAPER and TORN RED PAPER under 302's door. The one from 102's fridge is the only one 100% required, but they are all needed to collect all memos.