I'm not sure, but download from your server a file and delete from the server via ftp access(filezilla etc) or do at first a BACKUP, i'm not sure :x Try look ant the folder " Plugins " (yourdomain.com/plugins) and delete something with "2step Authentication" I want to know why you can access the Admin panel? At first you must enter a e-mail adress and password, then click sign-on/authentication button, the second step ist, you must go to your E-Mail, and find a e-mail letter from your communnity with the authentication code, go back to your Admin CP, enter email adress, password and the code from email letter.