There is no such thing as adjustment on a hydraulic clutch. All you have to do is change the fluid annually as you do with the brakes. If you percieve a problem, begin by bleeding the system.

What makes you believe that there is a problem with the clutch?

I have an 88 five speed 300E that I recently applied for the half million kilometer badge. It took a long time to find it back in the mid nineties and I have enjoyed it immensely.