If your not sure how, I'd take it to a maintenance center and have them do it for you.
You could buy cleaners and flush kits and attempt to do it yourself with a T kit (not sure if they'll work on your 06..I had an Olds Aurora that a T kit wouldn't work on)....Of course only use Ethylene Glycol coolant. But if you're not sure of how to do it, why risk messing it up?[/QUOTE
EDIT... Dexcool:th_thumb-down: get that crap out of your system and run ethyl
This vehicle has a newly developed engine coolant. GM Goodwrench® DEX-COOL® was developed to last for 240 000 km (150,000 mi) or 5 years, whichever occurs first. Follow the instructions in Draining and Filling Cooling System. Make sure only GM Goodwrench® DEX-COOL® (silicate-free) or Havoline® DEX-COOL® is used when coolant is added or changed.