Can I do this in a crockpot? What changed would I make?

Of course you can do it in a crockpot. You would just add water to barely cover the corned beef in your model of pot. It will cook on high in about 4 1/2 hours, or on low for 8-10 hours. Once the meat is cooked, you can tip the liquid out into another pot and cook the veggies as directed in the recipe from there.