I am not a noob and I am having the same problems with an upgrade to 6.2.0. I am locked out of the admin area with the CSRF errors and it won't let me do anything. I have uploaded all the files, renamed the admin folder to the existing folder and the admin.php file as well. Still, can't get in. Cleared the browser cache every time, did not help.
Other than a clean install and reinstalling the database what the heck can I do?
I am terrified to update other stores at this point. Also, why do the admin files never get updated when doing an update anymore? Seems like a huge problem.