John Gill Commentary 2 Chronicles 30:14

"And they arose and took away the altars that were in Jerusalem, and all the altars for incense took they away, and cast them into the brook Kidron." — 2 Chronicles 30:14 (ASV)

And they arose
Before they slew and ate the passover:

and took away the altars that were in Jerusalem ;
which Ahaz had set up in every corner of Jerusalem, to offer sacrifices upon, (2 Chronicles 28:24)

and all the altars for incense took they away ;
for as there were some to offer sacrifices on, there were others to burn incense upon, not to the Lord, but to idols, as the Targum adds:

and cast them into the brook Kidron ;
having reduced them to dust and ashes, see (2 Chronicles 29:16) .