itch.io

you see the items around the body? 

you use them, to cut open the body, its the knife, with the ribs you use the hammer and then the tweezers for the desired  organs and once you've collected them, you can say done on the list of organs

hope this helps!

You have to Skip Class with Sol and Hyugo in day 2 (from what I remember), choose to go to the cinemas, the character will want the bathroom (there will be a scene from that point) and then see for yourself

(btw this is from memory if i get something wrong, sorry bout that)