I am assuming the vehicle you have has the 5.8L V-8. To replace the EGR valve on this is relatively easy and so is cleaning passages. The EGR valve has a small vacuum line attached at the top and a flexible metal tube threaded on to the bottom of the valve assembly. The valve is bolted to the intake manifold and when you remove the valve there is a large orifice exposed. That orifice gets restricted with coked up oil residue, clean any particles and goo out of the orifice you can. You can use carb cleaner to do so, but use it sparingly, too much can hydraulic the motor and cause damage. Be sure to clean the mating surface where the gasket goes as to prevent any leaks. Make sure there are no cracks in the metal tube to the EGR valve, they can split and cause and exhaust gas leak. After you replace the valve be sure to have the codes cleared, if you do have a scan tool to do so, disconnect the battery (with the key off) for a few minutes, then reconnect it, that should clear the codes. Good luck