where is the PCV valve located in the engine compartment and how to replace it?

I just want to know where the PCV valve is in the engine compartment and how to replace it and how often it must be replaced and whether the engine will seize up with the old PCV valve forming sludge in the engine, is it going to seize up even if I do three month interval bulk synthetic oil changes at Walmart every less than 3,000 miles in three months to combat engine sludge and is Advance Auto Parts' Autotecnica PCV valve an acceptable aftermarket PCV valve?