Log in to your school's official website. You should have a previously issued user name and password for accessing your school account and records. If you never created an online account, you can usually register for one on the website.
Click on the link that allows you to view your current class schedule. The title of this link varies by university, but generally it's called "Courses and Registration." This should lead you to a page showing all of your registration and account information, such as tuition payments made and past course schedules.
Find a link corresponding to your current classes. It may read "View/Modify Class Schedule" or something similar. Click on this link to view your classes for the current semester.
Find the class you want to drop and click on its link. This should lead you to a page showing all of the details for the class. Make sure it is the class you want to drop.
Look for any link related to dropping the class. The link may say "Drop" or "Drop This Course." Click the link. You should receive a confirmation page asking if you are sure to want to drop the class. Click "Yes" and wait for a final confirmation page indicating that you officially dropped the class. Print this page and keep it in your records in case you need to show proof of the cancellation.