Uh, does it not work? There should be HID-compliant drivers built into XP64 that work with it. Or do you mean the software Logitech makes for assigning buttons and stuff? It seems like they never ...
To fix a problem with a Logitech trackball button, you don't have to solder anything or do anything else not expected of an average user. While Logitech doesn't provide troubleshooting tips ...