Leviticus 4:8-12

4:8 “‘Then he must take up all the fat from the sin offering bull: the fat covering the entrails and all the fat surrounding the entrails, 4:9 the two kidneys with the fat on their sinews, and the protruding lobe on the liver (which he is to remove along with the kidneys) 4:10 – just as it is taken from the ox of the peace offering sacrifice – and the priest must offer them up in smoke on the altar of burnt offering. 4:11 But the hide of the bull, all its flesh along with its head and its legs, its entrails, and its dung – 4:12 all the rest of the bull – he must bring outside the camp to a ceremonially clean place, to the fatty ash pile, and he must burn it on a wood fire; it must be burned on the fatty ash pile.

Leviticus 4:34-35

4:34 Then the priest must take some of the blood of the sin offering with his finger and put it on the horns of the altar of burnt offering, and he must pour out all the rest of its blood at the base of the altar. 4:35 Then the one who brought the offering must remove all its fat (just as the fat of the sheep is removed from the peace offering sacrifice) and the priest must offer them up in smoke on the altar on top of the other gifts of the Lord. So the priest will make atonement on his behalf for his sin which he has committed and he will be forgiven.