My '91 300SE from Texas has the EGR sitting right up on the exhaust manifold.
I've had to replace it once; it came right off with two bolts and didn't even tear the gasket. No real carbon buildup on the underside; I guess that's because it stays very hot sitting right on the manifold. However, the pipe runs from there around the back of the motor and into the underside of the intake manifold. That's where the carbon clog occurs. I've heard about running an old speedo inner cable thru the pipe to clean it out, but on the SE it's pretty asccessible from underneath.
A quick way to check if it's clogged is to idle the car, pull and plug the EGR vacuum line, and then apply vacuum to the EGR via a MightyVac. If the engine stumbles the EGR line to the intake manifold is still open.

DG