1. 1.   Turn off water supply to the sprinkler system at the main valve located in the basement.  (Usually at the water meter)
   

2. 2.    Turn on each station or sprinkler zone one by one going through all of them through your control box. (You will see nothing come on if you shut the water off correctly. This releases the pressure in the underground sprinkler pipes.)
   

3. 3.    Leave the timer on the off position or rain off.
   

4. 4.    You can also take a flat head screwdriver and go to the back flow device if located outside and open the ports with only 1/4 turn each. (usually 3 ports and you will see a gush of water come out of the bottom of it.
   

Quick freeze protection does not mean it is winterized for winter, it only releases the pressure out of the water lines.