Raise the door trap to open the wooden door.

Enlarge the gap of the wooden door opened slightly.

Get the square part and put snow into the empty can that you obtained earlier.

If you check with the binoculars, you can see a string that cannot be undone.

Move to the workbench where there is a knife stuck into it and enlarge the knife.

Use the binoculars on the knife and obtain the string.

Join the string and the hook.

Move to the wall with an elevator and enlarge the drainage outlet on the floor at the bottom left.

Use the String with hook attached to get the knob.