How do I uninstall a Kernel Extension in Yosemite?
I wouldn't go playing with kexts. They don't like being dragged around. You'll end up with a kernel panic and have to pick it apart in single user mode - let's leave that kind of thing to the hackintosh kiddies.
Logitech Control Center (LCC) comes with an uninstaller in /Applications/Utilities which would be a far better bet.