Regardless of why you want to get in, unauthorized access is illegal. So we can't tell you about it. If you really wanna know, just post and ask. Or you could use one of the recent suggestions for getting an IP. Run a webserver, and post a link to this guestbook, and maybe the person will go to your link.
What you're asking is against site rules, so I'm closing it. In the future, read the rules before posting, and read the other topics in the forums.