I was, really stupid of me. Afterwards when i tried to delete the files, i lost FTP-connection to my xbox, and now i can't get it again...

So, when i boot up my xbox i only get an entirely black screen with no errors or anything on it, and i can't acsess it via FTP... The box will on the other hand will lauch games (cold booted), clearly i've fuck'd up the dashboard (which was XBMC) .
Help anyone?