Wrong section. Your problem is with XBMC, and if you'd read enough to work out that you should post XBMC problems in the XBMC section you might have actually read some of the existing posts there, some of which contain the answer. Alternatively, you could have posted in the newbie section, where you'd get a lot more tolerance.
Press white + Y as the Xbox boots. It will put you into recovery mode with FTP access.
This post has been edited by Heimdall: Nov 5 2010, 11:15 AM