en_tn/lev/04/30.md

The priest will take some of the blood

It is implied that the priest will catch the blood in a bowl as the blood drains from the animal. (See: rc://en/ta/man/jit/figs-explicit)

horns of the altar

This refers to the corners of the altar, which are shaped like the horns of an ox. See how you translated this in Leviticus 4:7.

all the rest of the blood

"all the blood remaining in the bowl"