en_tn/2ch/34/03.md

the eighth year ... the twelfth year

"year 8 ... year 12." See how you translated this in 2 Chronicles 14:2. (See: rc://en/ta/man/translate/translate-ordinal)

he began to cleanse Judah and Jerusalem from ... the cast metal figures

This speaks of Josiah getting rid of the things that were used for worshiping false gods from Judah and Jerusalem as if he were making the places physically clean. Josiah would have commanded his workers to remove these things. Alternate translation: "he began to make Judah and Jerusalem acceptable again to Yahweh by having his workers remove from them the high places, the Asherah poles, the craved figures, and the cast metal figures" (See: rc://en/ta/man/translate/figs-metaphor and rc://en/ta/man/translate/figs-metonymy)