How to remove your gas tank from your Corolla GT-S in 10 steps.

Step 1
Open the trunk and unscrew the access port for the fuel pump and level sending unit. Then unplug the two sets of wires and tuck the ones on the tank side under the trunk floor through the port.

Step 2
Remove gas cap and unscrew plastic 'shroud' just below the mouth of the filler neck.

Step 3
Put a large drain pan under the tank (large enough to hold the amount of fuel present) and use a 3/8" drive ratchet to unscrew the fuel drain plug at the bottom of the tank. Screw the plug back on when done and remove drain pan.

Step 4
Jack up rear of car and keep up with jackstands placed under rear axle as far outboard as possible. Remember, it has to be high enough to clear the height of the fuel filler neck once the tank is on the ground.

Step 5
Place a jack under the tank with a piece of wood (a 2 by 6 about a foot long works good) between the jack and the tank. Just keep in place snug without exerting so much pressure that the rear of the car starts rising.

Step 6
There are two straps that pivot from the rear of the car and are bolted up to the floor in between the front of the tank and the rear axle. Remove the two bolts in front of the tank and lower the straps.

Step 7
Using the jack, lower the tank about 8". Now the hard part: You will need pliers and a couple of wrenches, I cant recall the sizes. Safety glasses are a good idea too to prevent dirt from falling into your eyes. Crawl under the car towards the front of the fuel tank and undo the fuel pressure line with the two wrenches. Be careful not to damage the mating surfaces of the two unions. With the pliers, depress the clips that secure the vent hose and the fuel return hose and slide clips several inches down the rubber hose so that you don't lose them. After that undo the rubber hoses from the steel lines, if you think you might forget which hose goes on which line then it is probably a good idea to label them.

Step 8
After all fuel lines and hoses are no longer secure, lower the tank as far down as you can while keeping the straps out of the way so that the tank will slide out towards the back of the car. If not you will either have to raise the front of the car to get it out the front or you will have to undo the straps from the back of the car to get the straps completely out of the way.

Step 9
Slide jack out from under the tank and allow it to gently drop the rest of the way. After ensuring nothing is interfering or still attached, slide tank out from under the car.

Step 10
To reinstall, follow removal instructions in reverse order.

Also**
Never just drop the tank straight down. It must be lowered while being pulled towards the rear of the car. If not you will bend the fuel pump hardline that faces the Front of the car.

If your doing this to replace a fuel pump its also easy to just cut away a little bit of metal around the cap where the sender unit/fuel pump plugs go in, At most you need to cut only an inch or so and can be done w/ a dremel.

This way you can remove it from the top, inside the trunk.

NOTE: Isn't there danger of spark when cutting metal with a dremel tool near the fuel lines?

There is , but the main line coming off the fuel pump is a hard line thats pretty thick. If your worried about it, there is a drain that is very easy to get to on the underside.

Just use a little bit of cutting fluid to keep this cool if you want to...
that should stop the sparks from flying.