Beat your friend up..... that's it...
You can make new IP and new chars most likely. But leaving a friend at a connected interface is a bad move. See to many friends "thinking" it'd be hilarious just to mess with your friend... Ends up getting banned and whatnot.
If you see the other post, some guy's friend actually deleted his char. Nice huh?
As far as I know, the IP your char is under is banned.