I agree that Dexcool isn't as big of a problem as most people think it is. I will give you that.
But the fact of the matter is that Dexcool still has its issues that you need to deal with. And that is why I changed mine out, in every vehicle I own.
The way I went about it is this. I first drained all the dexcool out I could. I pulled the radiator hoses, t-stat, knock sensors, etc. Let it drain, blow it out with the air hose, etc. Then I put it all back together, and filled the cooling system with water, right from the garden hose. I ran this for an hour or so, doing errands around town. Then I drained the water out, and put new water in and drove it some more. When the water coming out of the radiator was as clean as the water going in, I stopped. I then opened everything up again, hoses, t-stat, knock sensors, etc. and drained all the water really well. I then put in a 70/30 coolant/water mix. Since I couldn't get all the water out of the engine, I used a more coolant mix. I did have to use a hygrometer to test the coolant a couple days later to make sure I was where I needed to be, and I had to add a little more water. But now everything is great.
And FWIW, I did this over a couple days. I didn't make any special trips with the car or anything. Just drove it normal to and from work, and wherever we went. Then every night or so, I would drain the water. Took about 5 drain and re-fills to get everything clean.