I have an '84 380SL that won't start due to the ignition switch lock mechanism having a problem. The key turns only part way but not enough to fire up the engine. The locksmith can solve the problem but I have to remove the assembly and take it to him for repair. The question is 'how difficult is that to do and does it require special tools??' It looks like I have to take apart quite a bit before getting to it. My other option is to have it towed to a mechanic and have them do it. Opinions???