No need for two threads m'dear

It's not too hard a job, I'm assuming you're talking about a standard Cavalier and not a Turbo sinse the fuel tanks in them are different.

If you've got a basic toolkit and 13mm socket and extension you can do it, you'll also need some fuel line clamps, or if you haven't got them a few mole grips can do the trick but be carefull of they may damage the lines.

The fuel tank is held in place by two straps underneath the car, IIRC the straps are secured at the back part of the tank by the fuel filter with 13mm nuts. Other than that I think it's just screwdrivers for jubilee clips on the fuel lines and filler pipes.

Remember to disconnect the fuel line and pump wiring to the internal pump before you drop the tank, if you lift the rear seat base on the driver's side in the back and remove the plastic plug you'll see the fuel pump.

You'll need to get the car quite high on axle stands or on ramps to get access, axle stands will be better because I found it easier with the wheels off personally.

 

I have normally dropped the exhaust rubbers off as well , it just gives a bit more clearance to get the tank out .