Cannot acsess blogsite

Hello
I’m needing help with assessing a Blog, http://www.anarchysurfboards.com/wp
I’m seeking advice and support for a friend who has a blog But is not pc savy & can not log into his blogsite..
He can’t access it at all (gets a blank page)
He thinks he may have deleted it, when trying to change the theme..What can he do to recover it..(He told me..” I was changing the theme of my site with one of those wordpress featured themes but cant log into the dashboard or website”)

Thanks in advance for your replys.
Michelle Nixon aka Mooozy