Address book phishing and laptop "ownership"

I got an invite from someone I hadn't heard from in a while and I thought it was legit.  I clicked on it.  Unfortunately, it was one of those threat actors that extracted my address book and started sending mail to everyone.  It's been weeks and it's still doing it.

I am retiring that email address, but as it is still active as I tell people.  I have the legitimate mail from it sending to a new address.

I have a passkey on that address and Defender and Malwarebytes on my Microsoft Surface laptop.

Unfortunately, I just realized that address is the "owner" of my laptop.  I don't know how to change that account without losing a lot of info or access or?  How do I change that address?  Thank you.