Yes, leave out the smoked ham hock and the ham. Use vegetable broth instead of chicken broth. You may want to add more veggies such as potatoes or celery and more seasonings. Much of the flavor in traditional split pea soup comes from the pork, so you have to make up for that or you'll get a very bland soup. I'd add a good amount of aged Parmesan cheese if I were you. You might also try some smoked paprika or a touch of liquid smoke to replace that wonderful flavor of the smoked meat.