If we trust Biblehub's parsing information, yerek is in the construct form, hammizbeah is in the absolute form with the definite article, and saponah is in the absolute form with a 3FS possessive prefix. Thus, וְשָׁחַ֨ט אֹתֹ֜ו עַ֣ל יֶ֧רֶךְ הַמִּזְבֵּ֛חַ צָפֹ֖נָה לִפְנֵ֣י יְהוָ֑ה might be rendered, "And he will slay it upon the side of the altar, her north, to the face of YHWH."
Now, this might make sense if "her" referred to the altar, but that's impossible because the word for altar is masculine. Thus, I am puzzled trying to decipher the grammar of this verse.
How would you explain the grammar of יֶ֧רֶךְ הַמִּזְבֵּ֛חַ צָפֹ֖נָה to an independent Hebrew student?