After you wake up head out your room and down the stairs back into the dining room. You'll pass your mother on your way down and she may give you a chore to clean up your room. If she does head back into your room and dump the toy cars in the toy box near the door.
When you get to the dining room head for the left side of the room and you'll find a large door near the piano.
Enter the door, turn left and enter the bathroom at the right side wall of the hallway. You'll find Ivor inside and you'll also receive your target confirmation.
Inside the bathroom you'll notice that there's a wrench beside the toilet. Take it then head back into the dining room.
In the dining room approach the piano, make sure that no one is around then rig the piano using the wrench that you stole from the bathroom. Holster the wrench afterwards and go back to the bathroom.
There's a pen on top of the side table beside the toilet. Take it then use it on the little notebook right beside it. Lucius will add "Fix the piano" on the checklist.
Head back to the dining room and go to the corner right beside the living room. There's a cross here. Turn it upside down si it doesn't mess with your powers.
Now press 2 to equip your telekinesis and wait for Ivor to crouch down and get under the piano. When he does use your telekinesis on the piano until it falls down and kills him.