Things you'll need....
1. Plastic tank complete with pump and plastic fuel lines all down to the fuel filter and steel fittings, and the 5/8ths vent hose from the charcoal canister on the new tank
2. Filler neck and fill hose from the car that the tank came from.
3. Fuel tank straps from the car with the plastic tank.
4. 5/8ths double sided barbed fitting
15mm swivel socket and a long extension and socket wrench 3/8ths drive.
5/16ths socket or flat screwdriver for hose clamps
10mm socket with short extension
Floor jack, chocks, and jack stands
1. First step is to make sure you have a nearly empty tank or pump all the fuel out into a gas can. This is up to you on how you do it. I used a fuel pressure gauge attached to the fuel rail with a drain hose on the other end of the gauge while jumping the fuel pump relay to pump the tank dry.
2. Jack the car up by the rear subframe and put jack stands on the rear unibody frame rails to hold the car up.
3. Disconnect the fuel lines at the filter and drain any remaining fuel into a small drain pan. These are clip together quick disconnect lines. I find a pick or small flat blade screwdriver may help you get these off.
4. Remove the access panel in the trunk by removing the 10mm speed nuts and disconnect the electrical connectors and the fuel lines at the pump.
5. Pull the left rear tire and the rear wheel well splash guard by removing the 2x10mm speed nuts and two Phillips head screws exposing the charcoal canister and vent solenoid. remove the 10mm screw from the canister bracket and you can remove the canister. Make sure you unplug the vent solenoid electrical connector and remove the quick disconnect vent line. You'll need the 5/8ths vent hose attached to the solenoid and the canister so remove it from the canister and set aside. The plastic tank has the charcoal canister attached to the tank. You'll use the new one.
6. Time to get under the car and disconnect any and all quick connect lines that you can see. There are a bunch, it's pretty ridiculous.
7. Using a long flat blade screwdriver or the 5/16 1/4 inch drive socket with a long extension, loosen the hose clamp holding the filler tube on the back of the tank and pull the hose off the tank.
8. Place the floor jack with a piece of wood on it under the gas tank to diffuse the weight. Jack it up just enough to start putting pressure on the tank. Use the 15mm swivel socket, extension, and socket wrench to go through the rear subframe and remove the two 15mm bolts holding the tank straps up. Once removed, pull the straps down and let them drop. They'll pivot on the front joints.
9. Pull your exhaust hangers off up to the donuts holding the downpipe on and let the exhaust sag, you'll need to do this for clearance to get the tank out.
10. Slowly drop the tank down until you can reach up and disconnect the vent line from the tank to the charcoal canister, being careful to let the filler port on the back of the tank not hang up on the rear subframe. Slide the tank out and remove any other old quick connect lines under the car.
11. Feel free to do any cleaning, rustproofing, undercoating at this step since you'll have a ton of room to work with. If not, at this stage you'll remove the old tank straps and install the new ones for the plastic tank. This can be done by pivoting them out of the forward slots in the floor.
12. This is optional if you have the new filler spout. Go ahead and install it with the fill hose from the car you got the new tank from. If not, you'll have to cap off the vent line on your filler spout and cut and extend the fill hose by 2.5 inches with a 1 inch diameter by 4 or 5 inch piece of exhaust tube or galvanized plumbing tube and hose clamps. this is because the fill port on the new tank is 2.5 inches further to the right on the new tank because the charcoal canister is built on the new tank.
13. Remove the exhaust heat shield from the plastic tank and set aside for now. You'll put it back on once the tank is up. Slide the new tank up in place and jack it up careful that the fill port clears the rear subframe. Route the vent hose from the charcoal canister on the tank towards the previous location of the old canister.
14. Attach and start the bolts for the tank straps by a few threads, then go up to the access port in the trunk and attach the electrical lines. These are easier to connect with the tank down just a hair for more finger room. Back under and run the bolts up tight for the tank straps and remove the jack. You can reinstall the exhaust heat shield now that the straps are in place.
15. Attach and clamp down the filler hose to the tank, and attach the fuel lines at the filter and return. There's a slight change in the evap line connection. On the new connection it's the same style as the fuel line quick connect with the little plastic retainer instead of it being a squeeze and release. You'll see what I mean when you're down there. . You'll need to take the quick disconnect plastic retainer off the return line connection on your old fuel pump and use it to connect the evap line to your steel line by the fuel filter.
16. Attach the new 5/8ths vent hose to your old one with the bared fitting and run it back into the wheel well where your old charcoal canister was and attach the vent solenoid to the bracket in there from the old canister. Plug in the electrical connector to the solenoid.
17. Reinstall the inner fender liner and reinstall your left rear wheel and lower the car on to the ground.
18. This is an important step as the newer style fuel pumps aren't a dual speed pump, you need to remove your passenger headlight and locate the connector for your fuel pump resistor. Cut the wires on the resistor side of the connector and splice them together with an all weather crimp connector. This will ensure that the pump gets full voltage.
19. Put gas in the tank from what you removed from the old tank and cycle the key a few times to build pressure. Fire it up and check for leaks and you're done!
One thing I noticed right off the bat is the newer fuel pump is WAY quieter than the one in the steel tank. This is also a great upgrade to consider if your tank is rusty and looking like it won't last another salty winter. When I removed the old tank I was amazed at how rusty it was and how it hadn't leaked yet. The bottom of the tank looked great, but the top and sides were rusty as hell. Hope this helps anyone considering a tank swap. As far as I know I'm the first to do it since there are no other threads on it on the several forums I belong to.