Cook till nicely colored. Even direct low or med heat will work depending on how long you want to cook.
Foil with a small amount of liquid ,1-2 tbsp is plenty, until they are the tenderness you want.
Unfoil and firm up. You can glaze them now if you want.
I have done ribs this way direct on a kettle in zero degree winter weather. I have done them on gassers too. They will turn out fine. KKruger details variations of this method with high heat rib cooks. He doesn't always foil. If you want fast, easy, and tender..... Do this 3 step cook with foil.