URL changed – how to edit site documents to get into site

Hello,

My friend has forgotten to renew her domain and now has lost it. She has registered a new one and the site is now live. The site files somehow need to be changed to reflect the new domain name as even the login is pointing to the old domain name, so I can’t log in to her wp installation to help her. The blog is the root of the site, so although the site is ‘live’ it looks awful and the photographs in the posts are all missing, needing to be pointed to the new domain location. Fortunately she only has ever made 4 entries.

Can someone tell me which files need to have the old domain name changed to the new?

Anything else I should be aware of? It’s a real nuisance but she is completely unable to do anything to make it right and I am the one to clean up the mess.