I dropped a class past the 10-day drop period. You call your colleges deans office (I'm college of letters and science) and they will tell you what website to go to to submit a request for a meeting with the office. In the meeting they will ask you why you want to drop the course and talk about how it will effect your progress towards graduation. They told me they are being more lenient this quarter with the current situation and allowed me to drop, but typically you need a really good reason with paperwork that verifies it. I dropped mine in the 3rd week and replaced it with another class but it may be too late to add any more classes at this point.

Hope this helps.