Unable to login in to a new site

Last week I helped a friend register and pay for the domain name hebedesouzaauthor.com and the site is visible at https://hebedesouzaauthor.com . However, it’s possible that I mis-typed the email address when registering, because my friends hasn’t received an email asking her to confirm her email address. Therefore, we’re not able to login and add content to her site. Before logging out on the day we registered, I did a couple of things, e.g. making the home page a static page.
A few weeks ago, she registered a blog name – blackbritishblog with the correct e-mail address and this has been activated.
Here’s what we want to do:
1) Cancel blackbritishblog
2) Activate hebedesouzaauthor.com. I assume this will involve checking whether there’s a typo in the email we registered and correcting that, or replacing the domain ‘blackbritishblog’ with ‘hebedesouzaauthor.com’, since that is already activated under the correct email address.
We need to edit the site in the next few days, so would appreciate a response to this as soon as possible.