Log into your eSims account at the CUNY portal at https://portal.cuny.edu/portal/site/cuny/index.jsp.
Click on the tab labeled "Registration" for the sessions you are currently enrolled in. Choose the session with the class you want to drop.
Click "Drop" next to the class you wish to drop. Ensure that the class you drop is the one you intended to drop. You can also choose to replace the class with another one.
Visit your college adviser if you cannot drop classes online. The adviser can help you register for and drop classes.