Not straight forward at all the egr cannot be removed on its own. Its part of the inlet and manifold and im pretty sure the exhaust manifold/turbo the lot has to come off aswel.
When I bought my focus it had a flat spot. All I did was clean out the inlet and egr best I could with a huge can of carb cleaner a rag and a big flat blade screwdriver. I cleaned loads of thick crap out. After I pulled the vacumn hose of the top so the egr valve stays shut and just popped a bolt in the hose.
The car run so much better after and has improved more over time. That was a year and half ago.