Unless you can find a way to use the fuel pump to suck all of the fuel out (not recommended), you should take it to a dealership. Regardless, you most likely will have to simply drop out the fuel tank.
There is a 17 mm drain plug in the rear left of the tank on the bottom, remove it.
The 2003 Impala has a 17 gallon fuel tank
the fuel tank capacity is 17 gallon
17 gallon / 64 liter unleaded fuel tank
Its a 17 gallon Tank
I do believe it is a 17 gallon tank.
17
17
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17 gallons
17 gallon