leviticus 1:5 And he shall kill the bullock before the LORD: and the priests, Aaron's sons, shall bring the blood, and sprinkle the blood round about upon the altar that is by the door of the tabernacle of the congregation. - Free Bible Online

      5. he shall kill the bullock--The animal should be killed by the offerer, not by the priest, for it was not his duty in case of voluntary sacrifices; in later times, however, the office was generally performed by Levites.
      before the Lord--on the spot where the hands had been laid upon the animal's head, on the north side of the altar.
      sprinkle the blood--This was to be done by the priests. The blood being considered the life, the effusion of it was the essential part of the sacrifice; and the sprinkling of it--the application of the atonement--made the person and services of the offerer acceptable to God. The skin having been stripped off, and the carcass cut up, the various pieces were disposed on the altar in the manner best calculated to facilitate their being consumed by the fire.

JFB.