Please help how to reset or clear scores to zero like install game for the first time in osx?

hi, i have question maybe someone can help me. how do i clear or reset all memory or cache from my game project? i want to clear all, especially for best time best score that already saved inside my game like fresh from oven ready for distribution? thank you

I already manually delete unity file inside ~/Library/Preferences folder too but when i open the game, the score is exist. So frustate me. Please help. I hope you understand my english.

Hi

PlayerPrefs.DeleteAll ();
//Or	
PlayerPrefs.DeleteKey ("yourKey");