How far are you on Resident Evil 4 when youre in the castle

Probably farther than you I passed the game already and the bosses in the castle are the servant aka one of the skulls that help the little "gentleman" and the "gentleman" himself. Tip: When fighting the skull boss go near a tank that releases cold air and shoot him then or stall him until the elevator comes up. Tip: When fighting the "gentleman" shoot the eye and the mouth will open up. Buy a rocket launcher or two and use it on the "gentleman" when it opens.