You will continue to get conflicting advice here as well. a lot of regulars here do not agree o which antifreeze is best, probably the only thing we do agree with is leaving the old stuff in too long is not going to be good.
First piece of conflict will be about the flush. Some are for flushing out the old stuff and some are not. My recommendation is that you never use any of those flush chemicals in your cooling system. They dissolve stuff, that is never going to be good. In my experience people have more problems with their cooling system right after using any of those chemical than at any other time.
A mechanical flush, that is opening all the drains, block and radiator and or removing the lower radiator hose and using a garden hose (or machine) to pump fresh water through the system does minimal harm, but it doesn’t do any real good either. A drain and refill is adequate. You should drain both the block and the radiator though.
Don’t use the green stuff. It has a short life in an engine that has a significant amount of aluminum. This might be a moot point however as I haven’t seen the green stuff for sale anywhere lately.
It is OK to use the orange stuff, Dexcool. Your system is designed for it. But you can also use any longlife universal antifreeze. These new antifreezes meet all manufacturers specs. Usually these new antifreezes are yellow or red in color. It doesn’t matter, just pick one, completely drain your old stuff out and refill with the new.
I do not flush, the few residuals left in the system will be less harmful than the potential minerals left from tap water. Its like an oil change, the little oil that remains trapped in the engine will not harm anything.
You also have to make another choice, premix or full strength. You don’t use the full strength at full strength, you have to mix it with water. If you buy the full strength, I recommend that you also use distilled water to mix with it. The premix uses a purified deionized water mixed with the antifreeze.
My preference is to buy full strength and mix it with distilled water at a 2:1 ratio antifreeze to water. It gives it better freeze and boilover protection and puts more anti corrosives in the system.