Take ownership of the folder first, then you will have sufficient
permissions to delete it. Do so from the security tab/advanced options in
the folder properties. You must go into edit mode on the Owner tab. Make
sure you check the box for it to propagate to subcontainers, and it may take
a bit for the change to run through. Once changed, exit the folder
properties entirely and reenter them, then change permissions for yourself
and delete the folder.