Accessing blog

I am taking over a blog for a client and the previous web developer/person who set it up is saying she has no record of the UN or PW and does not know which email she used and is not willing to try “lost your password”. Is there anyway we can get into the blog with no UN, PW or email? The blog is housed on her website in a subfolder.

I’m not sure which WP version is being used as I cannot access the Admin.

Thanks sooo much in advance!