2 Chronicles 33:15
And he took away the strange gods, and the idol out of the house of the LORD, and all the altars that he had built in the mount of the house of the LORD, and in Jerusalem, and cast them out of the city. And he took away the strange gods, and the idol out of the house of the LORD, and all the altars that he had built in the mount of the house of the LORD, and in Jerusalem, and cast them out of the city.
Manasseh was born during the fifteen years added to Hezekiah's life after Hezekiah prayed for an extension of life, and he became one of the wickedest kings Judah ever had, with one of the longest reigns at 55 years. His wickedness brought great trouble upon the kingdom. The verse belongs to the course of events leading to the Babylonian captivity, and connects that captivity with the people's transgressions.
Though exceptionally wicked, Manasseh eventually repented: after he was taken prisoner by the Assyrians he humbled himself, God restored him to his kingdom, he learned to know God, and God accepted him. His repentance and restoration is a marvelous instance of God's wonderful mercy. After he repented, humbled himself in captivity, and was restored and returned to Judah, he began his reform by removing the foreign gods, the idol out of the house of the Lord, and all the altars he had built on the mount of the house of the Lord and in Jerusalem, and casting them out of the city.
In doing so he began to undo his former evil and the profanation of the temple, repairing the religious profanation he had caused. He did this to abolish idol worship. His personal reformation thus took visible form in an effort to undo the evil he had done, though its outward success was only partial and evil results remained.