Unbinding Active Directoy login, now locked out

Hi there,

I'm helping my wife get set up to work from home and I've run into a big problem. We went to get her computer and took it home, but when we got home and started it up we weren't able to log in to her account on the computer. What I didn't know at the time was that she was connecting at her work via an Active Directory account.

We took the computer back to her work, and after working through a few password resets I was finally able to login to her computer, and then proceeded to unbind the account from Active Directory by following the instructions at https://support.apple.com/guide/directory-utility/unbind-from-a-server-diruda43d3f4/mac. Everything went well until I got to the very last step, in which the spinning beach ball took over and the Directory Utility stopped responding. I waited quite a while and finally had to force-quit.

After restarting the computer I could no longer login. I tried the user account with all the passwords that previously worked, and the admin account that allowed the changes required as part of the process of unbinding the account. It appears I'm locked out.

Know of any ways to get back in to set up a local user account so we can again gain access to the computer? I think this computer is running Mojave (but I can't say for sure).