Bearing in mind that the Torah (in Parshas Tzav) has already informed us that the Asham must be Shechted on the north side of the Azarah, why does the Torah see fit to write "ve'Shachat es ha'Keves bi'Mekom asher Yishchat es ha'Chatas"?
Rashi: Because, since the Asham Metzora differs from other Ashamos in that it needs to be placed by the Sha'ar Nikanor, 1 we might otherwise have thought that it is Shechted there, too.
See Sifsei Chachamim.
And why does it ad the word 'la'Kohen"?
Rashi: To teach us that regarding all Avodos that an Asham shares with a Chatas, the Din remains unchanged. Because we might otherwise have thought that, since some of the blood is placed on the ears and on the thumb and big toe, it no longer requires sprinkling on the Mizbe'ach.