Hilchos Maasei Hakarbanos 5:9

The sin offering is the only offering that requires applying the blood to the altar with a finger, as per Leviticus 4:6: “The kohein shall dip his finger into the blood.” There must be enough blood in the bowl for him to dip his finger into; he may not scoop out the blood with his finger.

Hilchos Maasei Hakarbanos 5:10

The kohein goes up the ramp and turns to his right, walking along the ledge. He first puts the blood on the southeast corner, followed by the next corner, which is the northeast. He then proceeds to the third corner, which is the northwest. Finally, he comes to the fourth corner, which is the southwest. He pours the remaining blood on the base of the altar at the corner where he finished, as per Leviticus 4:18: “He should pour all the blood on the base of the burnt-offering altar.” This means the base of the altar on the south side.