How do you flush antifreeze in 1996 sts?

To flush the antifreeze in a 1996 Cadillac STS, start by allowing the engine to cool completely. Remove the radiator cap and drain the old coolant by opening the drain valve at the bottom of the radiator or disconnecting the lower radiator hose. Once drained, close the valve or reattach the hose, fill the system with a mixture of water and coolant, and run the engine with the heater on high to circulate the fluid. Finally, drain the mixture again and refill with the appropriate antifreeze solution, ensuring that the system is bled of any air.