java reflection: Is it possible to override a private method by change method Id?

There's a .jar file, I need to change a private method implement in a .class file. That method below

private void vibrate() {
    Vibrator vibrator = (Vibrator)RongContext.getInstance().getSystemService("vibrator");
    vibrator.vibrate(new long[]{0L, 200L, 250L, 200L}, -1);
}

this private method is invoked by another another private method below

private void notify(Context context, Message message, int left) {
    boolean isInBackground = SystemUtils.isInBackground(context);
    if(message.getConversationType() != ConversationType.CHATROOM) {
        if(isInBackground) {
            RongNotificationManager.getInstance().onReceiveMessageFromApp(message);
        } else if(!this.isInConversationPager(message.getTargetId(), message.getConversationType()) && left == 0 && System.currentTimeMillis() - this.lastSoundTime > 3000L) {
            this.lastSoundTime = System.currentTimeMillis();
            int ringerMode = NotificationUtil.getRingerMode(context);
            if(ringerMode != 0) {
                if(ringerMode != 1) {
                    this.sound();
                }

                this.vibrate();
            }
        }

    }
}

I need to surround it with a if-block like this

private void vibrate() {
    if(xxx){
        Vibrator vibrator = (Vibrator)RongContext.getInstance().getSystemService("vibrator");
        vibrator.vibrate(new long[]{0L, 200L, 250L, 200L}, -1);
    }
}

so I just wonderred if there is anyway to change the private method implement, like change the method Id use ClassLoader, or something else.