1998 Dodge Neon fuel pressure regulator

While accelerating, car bogs down. Took it to Auto Zone, was told it "could" be fuel pressure regulator. How do I find and change the fuel pressure regulator? Is it difficult to do this and how long will it take to change? Was told the probable cause:
1. Oxygen sensor defective. 2. Fuel system running rich-check other codes first. 3. High fuel pressure-fuel return lne blocked or pressure regulator defective. 4. Fuel pressure regulator leaking. What should I do? HELP! Thank you!