I have a 55 Chevy Bel Air. Simple question I hope. I am trying to remove one of the parking light bulbs. Removed the lens but it does not appear that the bulb can be removed from the front. Examined the wiring under the fender and slid the rubber boot back off the socket. The socket twists a bit but will not come loose. Also the wiring plug at the back of the socket will not unclip. I suspect some corrosion is involved. I did not want to break the bulb or socket. What am I doing wrong. Thanks in advance.