You pretty much can't, because the library key is in Jessica's room in the bathroom under the sink so if you haven't found her yet then you need to do that first then the red ghost will appear.
So i can't get into the Basement to find Yuri as i'd need batteries/a light source as going into the darkness will make you get a special scene, but i can't go into the library because i need the red ghost to turn into Jessica, enter her room and get the key there (+ the lantern is there).. damn well i guess i'll see if there's a way i haven't thought of yet
Well yes but you can just buy batteries and get a flashlight from the safe, it's what I did just make sure you got the combination go up and to the right don't even need a key. That or you go could go through the lab and get a flashlight up to you batteries can also be found in the lab too, if you need the combination grab the west key and theirs a room with it the one with two beds.