Hey bud,
I've done exactly what you are pondering - box blade and old asphalt. If you have a smaller tractor then you can just lower one or two rippers on the box blade to get a smaller bite. Get a tip of the ripper up under the asphalt (might take a few tries/passes) then you'll be off to the races. It'll peel right up quite easily, most likely. Then as soon as you can, switch to the loader to start scooping up bigger pieces. Ideally you would break up the asphalt and re-use it after you re-graded the substrate.
Good luck!