[Quall999]

Well, the easiest way would be to just go in the hard-drive management from your dashboard and delete the save through the in-dash options.

The hard way would be to connect to your xbox via FTP, go into the E drive, and remove saves from the TData and Udata folder. For this, you must open one of the files in a text editor from each folder, in which would state the name of the game All folders are named in a hex format.

edit: or like above, use an xbox mem-manager app that will ftp to the xbox and allow you to manage it that way