Well, there is a video on YouTube about Xbox controller repair without soldering. Basically you flex the sensor, pull out the worn disc and replace it, and then flex it back. It won't work with them. The inner disks have a different shape and size. You have to solder them. I did soldering for a living a million years ago and it's pretty easy to do with a cheap soldering kit with a soldering suction cup. Anyway, the one I soldered worked fine with no drift. so that's a bonus.