cfm56, if you search under my username for my previous posts you'll see one entitled "For PD owners shuddering or stuttering at idle", in which i more or less described my experience with the EGR.
basically it's a simple job. the EGR valve is the round aluminum thing on top-left of the engine, right under cover, facing you as you open the hood. you'll see the air intake hose coming from the pass. side headlight going into the intake; well, the EGR is the valve that the hose leads to. all you have to do is undo the 3 hex bolts holding it to the intake manifold, i think they are 5mm, then twist it back and forth as you slide it out towards you. you'll most likely have some crud built up so be careful where that junk falls. make sure you unplug the electrical connection as well. after you have the valve off the intake, scoop up and loose carbon pieces that you can get your fingers to. don't scrape anything to dislodge it because it won't do much good unless you take off the whole intake, just to avoid getting crap into the engine and bending a valve :O remove the rubber gasket at the base of the valve, wipe it with a little alcohol and it should be fine to be reused. use a good carb cleaner spray and a bristle brush to clean out all the junk and make that valve shine like new, put the o-ring gasket back on, slide the valve back into place, handtighten screws then tighten them snug, reconnect elec. connector and get cleaned up. take it for a ride after hearing it idle a bit. leave the a/c off and all other electrical loads, just listen to the idle a bit before you drive off. if your EGR was crudded up as bad as mine was, you'll definitely notice a difference in the mid- to upper-range rpms. good luck, post back with results.