Research the Ivy League schools for distance education. Harvard has one of the easiest to find. It is the Harvard Extension School. Determine the admissions process, programs and costs. If it is just a couple of courses there is no admission requirement at most of the schools, but if you really want to earn a degree then you should plan your courses accordingly.
Pick your classes. At Harvard you must complete three classes before they will officially admit you as a degree candidate. You could do it during the summer, so you can get financial aid in the fall. You will have to pay for your classes upon registration.
Become familiar with the structure of courses. Harvard has two options--on campus or online. Because of the big deal of campus life they require some residency on campus. It can usually be done in the summer, or if you want you can actually go live in the college town and take the classes on campus.
Pay for your classes. Depending on whether it is for an undergraduate or graduate program, the tuition starts at $650 per class. Even with four classes you will not come close to spending the over $30,000 per year just for tuition at Harvard. That also applies on the graduate level.
Act like a college student: You have to do the work; if you do, you will be admitted into Harvard just on the basis of your GPA at their school.