I can see that I did not make myself clear. On my 95 C280 on three of the six spark plugs the wires go into some kind of electrical block that sits directly over the connector. The spark plug wires go into this block and the connetor is attached to the block instead of attaching directly to the plug. The other three wires go directly to their plug and they come out easily with a spark plug socket, no problem. On the three plugs that are in question the connector is attached to this block and the block in turn is attached to the engine with a very small, brass I think, slotted screw that is recessed and therefore impossible to grasp with any kind of pliers. Apparently when the previous owner changed the plugs or tried to, the slotted screw stripped and is now holding the block to the engine thus denying access to the plugs. I need to get the screws out somehow.
Maybe if someone out there has a similar setup they could add to this post and perhaps give a better description than I have.
To complicate things even more the screws aren't simple screws but part of an assembly that doesn't appear to have any real purpose beyond holding the block to the engine, but what do I know?
If I'm still not making it clear what the problem is I've noticed that some folks send pictures. I'll borrow a digital camera and see if I can get a decent picture to put on line. Owning a Mercedes is certainly expanding my horizons.