There is no pressure, just remove the EGR valve, after removal of EGR valve you should see a hole on the intake manifold, remove the idle air control valve bypass hoses, then remove the 5 12mm bolts that holds the intake manifold chamber and and disconnect the throttle body cables and remove the intake maniflod chamber. Then spray some throttle body cleaner into the EGR passage and use a hanger to clear up the passage.