Search the forums - do whatever you can to avoid disconnecting the battery. I'm not sure on the CLK, but on the C, it's only one torx screw holding the changer in the glove box - it's at the top of the bracket - and then the changer slides sideways to remove. You could then remove the power to the changer by unplugging it rather than trying to disconnect the battery in your car..Many thanks. I will try it.
Why do you say that about the battery? If I have never done this before. Can disconnecting the battery cause problems?
If you decide to after all, see post #14 at http://www.benzworld.org/forums/w220-s-class/1302190-ive-had-2.html#post2216730 for the resets you may need.Ok I will not disconnect the battery.
Many thanks again all.