There is a prerequisite for this instructable - https://www.instructables.com/id/RX300-Removal-of-Back-Seats/
The fuel pump is located under the driver side back seat. You will probably find that it is easier to have both back seats out of the car in order to flip the carpet forward out of the way while you work. Also, it gives you an opportunity to clean while you have the tools out anyway.
Remove at least the driver side rear seat and flip the carpet forward out of the way.
Step 1: Accessing the Top of the Pump
There is a large, 6" diameter cover with a wire harness coming out of it. You will need to pry very gently, but firmly for a prolonged period of time. The sealant will slowly release and the cover will let go. Do not get this sealant material on any clothing you care about, it doesn't like to come off.
There is a short run of wire harness between the cover and the top of the pump. Press the connector catch by squeezing with your thumb and gently wiggle and pull the connector off of the top of the pump. The wire was too short to put my hand on it and show you how to do this, so the description will have to suffice.
Once the wire is disconnected, you can easily set the cover to the side.
Step 2: The Invisible Fuel Line Clip
In the previous image on the last step, you will not be able to see this clip. It was covered in road dust and took a minute to figure out what was holding the fuel line, I cleaned it and set it in its relative position for this photo.
Simply use a small flat head screw driver to gently pry the clip out.
Note: The clip has a little spring to it and it will shoot when it finally lets go. Push a rag into the surrounding area so that you don't lose the clip.
Step 3: Back Pressure Will Push Fuel Out the Top
With the clip removed, you can gently pull straight up on the line to remove it from the top of the pump. However, don't do it yet. First use a combination of #2 Phillips head screw driver and #8 box wrench to loosen the 8 screws that make up the retaining ring. The ring will also be stuck on from age and vacuum in the tank. I needed to pry a little at the edge to make it let go. Looking back, I probably could have loosened the gas cap.
With the retaining ring loose, it is time to remove the fuel line - pull straight up gently.
My retaining ring did not fit through the hole. I simply moved it to what is the bottom right corner in this photo and let it rest on top of the tank. Next, lift the pump assembly out, being careful not to damage the attached hose, float and filter sock.
I couldn't do this and shoot a photo, so please look at the next step to see what it is you are extracting before you begin.
Step 4: The Pump Assembly
I was not expecting this giant coffee can kind of assembly.
After turning the assembly so that it rests on its top, I used a small flat head screwdriver to loosen the clips on the cap holding the filter sock. This is all fairly brittle, be gentle. Do not bend or otherwise upset the float, this is your gas gage.
Step 5: Removing the Assembly Top
Lay the assembly on its side and again use the flat head screwdriver to loosen the clips and remove the top as shown. You will be able to release the directional wire clip from the top of the pump.
Step 6: Removing the Pump
From here, you will grab the end of the pump with the strainer sock and gently twist back and forth as you pull away from the rest of the assembly. The "O" ring gasket and pressure from fuel inside the device will hold on very tight. Be patient, it will come out.
Step 7: Final - Match New Part and Position Then Re-assemble
This should be pretty obvious now, but place the new part in a position matching the way the old one came out and begin re-assembly with the new part.
Note: My replacement filter sock had a round elbow instead of a flat elbow. I used side cutters to clip out material and make room for the new filter. This also made a tight fit when placing the pump back in the car. Everything works great in my case. Reverse this process to finish the job.