I don't think you are missing anything. I do just as you have, except my wheel spindle unscrews and comes out ok. Soak in penetrating oil overnight and try again?
Take pinch bolt right out. Get a kettle of boiling water and pour over bottom of forks around axle. Should make alloy expand just enough to get it turning and out. Use a torque wrench and give threads on axle and forks a good clean and lube when rebuilding. I have a tin of Castrol LM grease thats perfect.