HELP! Can't access admin page.

Hopefully I can make sense of what I have done.
My wp site is in a sub of my root directory.
Attempted to move my wordpress site to my root directory.
I went into admin and changed the URL and URI path
did not work so I went to move everything back to where it was originally but now I cannot access the admin page to change path again.

Which file do I need to access via filezilla/dreamweaver to do this the backdoor method or is there another way to access admin page.

Hope this makes sense.