This letter is for informing your family that you've decided to change majors.
1234, Main Street
Boston, MA 02123
09 April, 2005
<Recipient Address Goes Here>
They say college opens your mind and helps you see things in new ways. In one case, at least, that's true. I've learned to see this: <your old major> is about as exciting as watching cars rust. I've decided to change my major to <your new major>. It may not sound <description of new major> to you, but it's really interesting to me. So I'm going to give it a shot. I think I'll actually be able to stay awake in class now! I hope I can count on your support.
encl: <List of enclosed items goes here>