The Course Selection II Period is your opportunity to make further changes to your registration and runs from July 29th to August 2nd. During this time, most enrollment restrictions on courses will be removed and remaining spaces in classes will be open to all Arts and Science students who have the proper prerequisites (if required).
During the Open Enrollment which runs from September 4 to 20, 2013, you may only make changes to your classes if you have paid your tuition in full! If, after attending one or two classes you find a course is not for you, you can drop it and add another course in its place (just remember that you will need to catch up on any material you might have missed!).