Perforce depo converted to streams; can't delete old files from non-streaming client

I have a depot that was originally built as a non-streaming storage. We added some files when sorting the folder structure. The store was then converted to a stream store and I want to delete the old files.

Unfortunately, these source files do not appear under any stream, so I cannot remove them from the client stream.

I have a non-thread client left over from initial testing and I can open the offending files for deletion, but I cannot send them:

//depot/myworkspace/main/foo.txt - warning: unable to send from client without stream

Is there a way to delete files on the client side? (Note that I am not an administrator on the server - my admin will be my next step.)