I have a 83 240D Sedan. The power antenna will not go down all the way when I turn off the radio. It tries but gives up after a few seconds. It basically goes from half up to full up but never all the way down. I was wondering how much work it is to remove and/or fix. Or is it something that is not too much $$ to just replace? I'm kind of a mechanical geek and I like all things to work properly just for the joy of it.