do a 180

do a 180

1. Literally, to begin moving in the opposite direction. (If one physically turns 180 degrees, one will then be facing the opposite direction.) I was going to go to the park, but when I saw those dark clouds roll in, I did a 180 and headed back home.
2. To make a big change in one's position, opinion, lifestyle, etc. A: "Can you believe that Sam quit his job at the firm?" B: "No, he really did a 180 on being a paralegal!"
See also: 180
Farlex Dictionary of Idioms.

do a one-eighty

 and turn one hundred and eighty degrees 
1. Lit. to turn around and go in the opposite direction. When I hollered, the dog did a one-eighty and headed back to its own yard.
2. Fig. to radically reverse a decision or opinion. His political philosophy turned one hundred and eighty degrees when he grew a little older.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • literally
  • drift with
  • drift with (something)
  • (the) survival of the fittest
  • beat the daylights out of
  • beat the hell out of
  • beat the living daylights out of
  • beat the living daylights out of someone
  • beat the tar out of
  • beat/scare the daylights out of somebody