Fixed My One X!
I've had the same problem. I thought my bad wifi signal was gonna improve with updates so held out and guess what my 30 day return policy expired so would have to relock bootloader and wait god knows how long to get it back!
I saw the guy who had took his apart and cleaned the contacts, so today with a bit of a sweat on I took mine apart, I cleaned the contacts and also very gently bent them upwards to make more contact and voila! Full signal outside in my garden!
Its actually quite easy if you are very gentle and have a lot of patience
Cracking open the htc one x, tech republic (sorry im new, cant put a link)
You will need a very thin metal tool, I used a feeler guage.
Be very wary of the thin connector at the bottom for the hardware buttons i nearly snagged mine.
make sure you take the sim card holder out first!
watch out for the power and volume buttons flying everywhere when you get it apart.
the power button is VERY fiddly to get back in, use some tweezers to position it in the back cover before you put the phone back in. same with volume buttons.
took me 15 mins. better than weeks!
HTC One X