Can't Access School Portal Files

I used to be able to access my box through my school portal. I've since graduated two years ago. I was able to continue to use the portal until today. Today, for the first time, it displays "invalid login credentials" and doesn't allow me to log in. I logged into my personal free account to post this question to the support forum:

How do I access the files stored on my old school profile?
I'd like to offload them or transfer them to my personal account.

Thanks for your help!