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!!!