Before we start, please note that this is not the official update for HTC One X and the process, least probably, may brick your device. We are not responsible about anything that may happened on your phone.
Android's latest and greatest OS, Android 4.1 Jelly Bean has a lot of amazing features. It's a good news for you HTC One X user because now Android 4.1 Jelly Bean can be ported to your device. HTC One X users can now upgrade their devices to 4.1 Jelly Bean prior to official release.
Everything works quite well except Wifi, radio, audio and camera. So it’s my responsibility to say, Do it at your own risk. If you can tolerate these bugs, you can proceed to taste the latest Android flavor. Here are the tutorial how to pot your HTC One X to Android 4.1 Jelly Bean from XDADeveloper.
You can proceed to try it here.