Albert Barnes Commentary 2 Chronicles 35:12

"And they removed the burnt-offerings, that they might give them according to the divisions of the fathers` houses of the children of the people, to offer unto Jehovah, as it is written in the book of Moses. And so did they with the oxen." — 2 Chronicles 35:12 (ASV)

They removed the burnt offerings - They separated from the Passover lambs those parts which were to be burned on the altar. They gave these parts to the people offering them, who then took them to the altar and handed them to the officiating priests.