How do I delete a guestbook post?

If you are website owner:

Click the icon next to the post you want to delete and enter your admin password.

If you posted a message in a guestbook:

You will need to contact the website owner (the website where you posted in the guestbook) to have the entry removed. I have no control over other websites and there is no magical password that would let me delete posts from other guestbooks.