1. Follow my previous post (it's right before this one) on how to get into the dev mode terminal.
2. Type dir /media
3. Then type cd -P (whichever device seems like the right one, without these parentheses. Make sure to be using correct capitalization throughout this process, or lack thereof)
4. Then type dir. A list of files from that device should come up.
5. After you've determined which file you want to delete, type sudo rm (file, without parentheses)
There ya go, deletion completed. A little message about admins and whatever should also come up after deletion, but it doesn't mean there was an error. Happy chroming! :)