Open the hatch above the toilet.
Place the blue object on the numbers, then use the hammer to break the numbers that are showing.
De-select the hammer, tap the blue object to move it, then use the hammer again to break the numbers that are showing.
Keep doing this until the blue object is gone and only 4 numbers remain. Remember the numbers from top to bottom.
Press the black screen on the door and enter the code, then press the arrow. The code changes every game.
Press the door to open it.
Proceed to the next 100 Toilets level!
Hit like if the 100 Toilets Level 20 walkthrough helped you! Thanks :)