Aiden's LockerPick up the hammer in Aiden's room and zoom in to find the right combination on it.
Mila's LockerMila's locker combination requires a bit more leg work and is split into two parts. The first clue is a ripped pice of paper on a table in her room. Pick it up and progress until you reach the lower deck. Find the conference room and search the large table for the second piece of paper. You can now check the solution to Mila's locker in the menu.