I'm guessing here, but try this:
Marinate your ribs in Coke for 24 hours. There are a lot of folks who think the acids in Coke will break down the meat fibers leading to more tender ribs. I personally don't agree, but if he wants Coca Cola ribs, he should have coca cola ribs. What WILL happen is you'll have ribs that have been marinated in a sweet/acidic marinade, which will taste pretty damn good.
After they've soaked in the Coke for 24 hours, take 'em out and pat 'em dry. Sprinkle on any dry rub that suits your fancy. Since you're going to be doing these in the oven, use something with smoked paprika as the main ingredient.
Set your oven to 300°. Put the ribs on a rack in a sheet pan. Check on them after 3 hours. They likely won't be done until 4 hours, but just make sure. You're looking for a temperature of 190°-200°. The lower the temp, the firmer the meat will be. Fall off the bone will be between 200° and 205°. Probe the rack between the 2 center bones, or the fattest part of the rack.
When they reach temperature, remove and sit on the counter, loosely covered in foil for an hour or until the temperature drops to 150°. Just let 'em sit for an hour, it'll be close enough.
Eat.
Enjoy.