Since the 5 years are almost up on the life of the Bonneville'* coolant, I decided to go ahead and change it now. Much to my surprise was the fact that there is no drain on the radiator. It'* hard to believe you have to take out the radiator to drain the system but I don't see any other alternatives. I did look around on the bottom of the block and found what I assume is the coolant temperature sensor near the oil filter. That would at least drain the block.
Am I off in left field or is there an easier way to drain the coolant?

The drain is located on the drivers side lower rad area, you need to remove the air dam for better access. First remove and clean the rad cap for better flow.

Completely drain the cooling system by opening the radiator drain **** at the bottom of the radiator.
If the coolant is dirty, or if there are deposits in the radiator, flush the cooling system before refilling.
Disconnect the hose from the coolant recovery reservoir. Remove the reservoir.
Clean the outside of the coolant recovery reservoir. Pour out any fluid.
Thoroughly clean the inside of the reservoir using soap and water.
Thoroughly flush the reservoir with clean water. Drain the reservoir.
Install the reservoir. Connect the reservoir hose.

Fill the radiator and the coolant resevoir (to the full cold line) with GM Goodwrench® DEX-COOL® or Havoline® DEX-COOL®. To ensure sufficient engine cooling, freezing and corrosion protection, maintain the protection level at -37°C (-34°F) lower.
Wait for two minutes and recheck the level of the coolant in the radiator. If necessary, add coolant to radiator until the coolant level is at the base of the radiator fill neck.
Install the radiator pressure cap, making sure the arrows on the cap line up with the coolant recovery tube.
Place the heater and A/C control in any A/C mode except Max and the temperature in the highest setting.
Start the engine and allow to idle until the lower radiator to coolant pump hose is hot.
Cycle the engine speed up to about 3000 rpm and back to idle five times. Slowly open the bleed valve on the top of the thermostat housing for approximately 15 seconds to expel any trapped air in the cooling system.
Close the air bleed valve. Do not overtighten.
Allow the engine to cool to outside temperature. Ensure the coolant level in the reservoir and the radiator are at the proper levels.

Found an eaiser way to do this today. Just pull the front knock sensor. Its probably clogged anyway and should be cleared out.

Easy to get to from under the car with long extension and you dont have to remove the air dam.

Sorry I didnt respond to this earlier, yea if you pull the knock sensor first it will drain most of the system. I didnt take off the rear one so not sure how much more would come from that side if any. Probably what is left is in the water pump.