Remove Education or Business Account from Mac

Hi, 

I have a personal account and a university account on my Mac. Now I no longer have access to my university account so I can't sign in. On load up my Mac signs in to my personal account however it keeps asking for my University login for the other. I would like to remove this prompt and the university account altogether. 

I have tried so far:-

 - Unlinking the account.

- Deleting OneDrive and reinstalling.

Also, I have the same issue on my main PC in which the folder for the OneDrive University accounts still exists and displays in the File Explorer menu (not quick access). However, when I try to delete or hide it, I get the message the File or Folder does not Exist. In this matter, I have tried a few operations in Command Prompt but still cannot get it to disappear.  

Any help on these would be great.