HD full. How to remove the pre-patch data?

MY SSD is full. I need to upgrade, ok. But for now, where are the files/folders of the pre-patch so I can delete them and get back my SSD into operational status?
I will tell bnet to install WoW in my former HD and than copy the whole folder back to the SSD after tuesday.

Howdy!

I commented on this Here.

Thank you.