Leviticus 4:3, 12, 21

if it is the anointed priest who sins, thus bringing guilt on the people, then he shall offer for the sin that he has committed a bull from the herd without blemish to the LORD for a sin offering.

all the rest of the bull—he shall carry outside the camp to a clean place, to the ash heap, and shall burn it up on a fire of wood. On the ash heap it shall be burned up.

And he shall carry the bull outside the camp and burn it up as he burned the first bull; it is the sin offering for the assembly.