How do I access the Drupal admin panel, when the login block is disabled?

Answer :- In those cases, we can access the login screen simply through the following URL.

http://sitename.com/?q=user

or if the clean URL is enabled

http://sitename.com/user

Similarly if you can’t access the logout link and need to logout, you can do so by using the URL

http://sitename.com/?q=logout

alternatively with clean URLs enabled you can try

http://sitename.com/logout