What was the specific DTC code? EGR valves don't fail that often; DPFE sensors OTOH do fail regularly on your model year. They were problematic on the early cars because heat and moisture would kill the internal electronics.
If the code was P0401 - EGR Flow Insufficient Detected, you may be barking up the wrong tree. Here's a quick and dirty preliminary test for the EGR valve: Engine off, remove the vacuum line from the nipple at the top of the valve. Apply vacuum by sucking on a clean piece of hose attached to the nipple. Release. You should hear the valve make an audible "clunk" as it closes. You should also feel the suction on the internal spring loaded diaphragm as you breathe in. That means the valve is opening and closing. That's all the EGR valve is; a vacuum operated, spring loaded "door". Sometimes they do carbon up and get clogged and get stuck open.
If the test fails and you really want to remove the EGR valve, remove the entire EGR tube and assembly. There are two ten (?) mm bolts where the tube attaches to the metal port on the intake manifold (below the valve body). Undo those, remove the coil to gain access and remove a couple more retaining clips as you work your way to the front of the engine. Loosen the large nut where the tube enters the exhaust manifold (which can be a problem in itself, but access is generally better than at the back of the engine. You may need to attack it from under the car.) Once the entire pipe and valve is off the car, then you can pull it apart.
But you'll be sorry for all that work if it doesn't cure your problem and your DPFE sensor is the part that's faulty. DPFE sensors take five minutes to replace. Investigate a bit further. My $0.02