I have a spare key ignition cylinder and keys that came with my 2000 986 Boxster - brand new in the the box, previous owner never got around to fitting it. My existing key and cylinder are clearly very worn and is becoming very difficult to turn and remove. Can I simply replace it with the new one without an expensive visit to the service dept? I have already changed the electrical ignition switch, later type steering lock and cleaned and lubed the existing cylinder with no improvement in the key turn. THANKS!