i have a 2004 Chevrolet Impala base with a 3400 V6 LA1 engine and its cooling systems states that it takes 11.3 quarts. I need help on to do this??????? Please help me noww!!!!!! Experienced Technicians are required to answer this question!!!

it takes dextron - antifreeze or equivelant - your car has cast and aluminum parts - the antifreeze needs to be appropriate.

Remove the lower radiator hose and drain it completly.
You can turn the water pump to flush the block - then refill and purge the air out

What we do at my shop is hook the coolant flush machine to the vehicle and exhange the coolant. It probably takes dex cool so dont put green in it. I suppose if do a shade tree flush, you can drain the radiator from the bottom and re-fill with coolant, make sure you bleed the coolant system afterwards or it will overheat.