root

public static boolean runChmod777(String myfile) {
        Process process = null;
                try {
                        process = Runtime.getRuntime().exec("su -c chmod 0777 myfile");
                process.waitFor();
                } catch (Exception e) {
                        Log.d("*** DEBUG ***", "Unexpected error - Here is what I know: "+e.getMessage());
                        return false;
                }
                finally {
                        try {
                                process.destroy();
                        } catch (Exception e) {
                                // nothing
                        }
                }
                return true;
    }