Remove the boards with the HAMMER (K); take the SHOVEL (L) and the BOARDS (green).
Walk down twice.
Remove the sand with the SHOVEL (M).
Take the PEROXIDE (N).
Go to the Sam's Room.
Read the recipe (blue); pour the SPIDER VENOM and the PEROXIDE into the flask (O) and take the ACID.
Go to the Crossroad.
Put down the JACK (P) and turn its handle; take the STEERING WHEEL (Q).
Pour the ACID over the chain (R).
Play the mini-game.