no worries! i hope what im saying is understandable, let me know if i need to rephrase anything!
when you get into the sewer you want to go to the room on the left of the screen and youll see a panel on the top of the next room. interact with the switches until the boxes in the previous room all line up into a pathway! you may want to press a switch and then check the other room to see where the boxes moved to get the order they need to go in ^w^ !