README

To install plugin you need:
1) Copy files to <Sublime Text plugins directory>\sublimetext_prettyjson. If you are not sure where is it located start Sublime Text and open Preferences -> Browse packages... In dialog opened you could copy path to plugins directory. 
For Windows 7 it is usually %APPDATA%\Sublime Text 2\Packages\sublimetext_prettyjson

2) Add key binding in Preferences -> Key bindings... like
   { "keys": ["ctrl+k", "ctrl+j"], "command": "prettyjson" }   

3) Done, now select JSON and press Ctrl + K, Ctrl + J