PLEASE HELP

I set up a wordpress blog on someone’s advice for a friend and they have lost the password and username. They want me to change something and we literally cannot access it in any way at all. None of the emails work. None of the expected usernames and passwords work–NOTHING. It is a free WordPress blog, with a domain name redirect so there is no server person to contact or anything else. I’ve spent 4 hours just figuring out how to get the login screen by adding (wp-login, yes?) to the blog address but nothing I type into the boxes works.

What do we do? It’s as if we’re in a black hole and there’s nothing at all we can do to get in or out of it.

Please help if you can.