You can get to it by removing the bottom of your back passenger seat, from there it should be quite simple. If you still need help, there is a great website dedicated to Toyota celica's... www.celicatech.com. Make an account and search the forums, someone on there can surely help you with step by step instructions. :]
drop the tank.......
its under the back seat
You will need to take the fuel tank off the 1991 Toyota Celica GT and remove the fuel pump and replace it. Always make sure to drain the gas before you take the tank off the car.
take it to a garage
very carefully
THERE IS NO FUEL CUT OFF SWITCH ON YOUR CELICA
Spray a small amount of carburetor cleaner in the air intake and if it starts it is fuel related.
Under the hood.
Mounted on top and inside the fuel tank.
Underneath the rear seats.
in the gas tank
if its fuel injected its in the gas tank