I recently acquired a second-hand HTC One X. A week or two back HTC decided to release the JellyBean update for the phone, all was well. Yesterday, another update was sighted on XDA, and since it seems like this one gives better battery life, I didn’t feel like waiting another 3-5 weeks before it became available in my country, so I searched on how to manually flash an OTA.
As always, this procedure comes with no guarantees it will work for you. It might as well decide to eat your cat, or turn your blood into liquid metal (if you don’t have a cat).