What modifications would I have to make when substituting veal for pork? I would like to make this recipe for Pork Osso Buco, https://m.youtube.com/watch?v=yNgna9mZoa4, but I'll be using veal beef shanks and not pork. 

Do I have to make any modifications like the time it's braised or seared?
In the particular recipe you've provided no change in the cooking method is required. The only thing to keep in mind when cooking veal is that it is a drier meat. In your case however, the recipe cooks the meat in liquid which moisturizes it. Keep an eye on whether it is cooked all the way through and always note recipe times vary! 
Hope that helps!