一改故轍

一改故辙
yīgǎigùzhé
  1. complete change from the old rut (idiom); dramatic change of direction
  2. a volte-face
  3. to change old practices

CEDICT

Entry Composition

1 一 yī
  1. one
  2. single
  3. a (article)
  4. as soon as
  5. entire; whole; all; throughout
  6. "one" radical in Chinese characters (Kangxi radical 1)
  7. also pr. yāo for greater clarity when spelling out numbers digit by digit
2 改 gǎi
  1. to change
  2. to alter
  3. to transform
  4. to correct
3 故轍 gùzhé
  1. rut (made by vehicles)
  2. (fig.) conventional ways