I tried starting my 1988 300 E and the key would only turn to the first click. after a little silicone spray and some tapping on the key, and wiggling a bit it just got worse. now it won't turn at all. The dealership wants $800 to fix it. they said 800 in parts. I see the ignition lock on here with a key is only 15.99. I've decided to try to fix it myself. Is there a possibility that the ignition lock is all thats broken? How hard is this to change and what does the job entail?