For the fuel line & fitting, clean off any rust and try spraying some PB Blaster on it, and let it soak a bit. A 5/8" or 16 mm flare wrench, and a 19 or 20 mm wrench for the filter. I'm guessing that filter is plugged up if it's been on a while. Recheck the pressure after you've changed it, and go from there. With the key on and the pump running, the pressure should be 48-55 psi. If the fuel system drops more than 5 psi in 10 minutes, check for leaks in one or more of the following areas: Fuel pump check valve, flex pipe (part of pump assembly), valve or valve seat in the fuel pressure regulator, fuel injectors. Inspect the fuel lines for leaks or obstructions as well. Good Luck!