Every drupal developer knows about drush and drush commands. If mistakenly you installed some broken drupal theme and you are not able to access site then you need change the drupal theme using drush command.
disable drupal theme using drush, Every drupal developer knows about drush and drush commands. If mistakenly you installed some broken drupal theme
disable drupal theme using drush
#drush vset theme_default seven
Using above command you can set the seven theme as default drupal theme. It will disable the your activated old theme.
Note: this command I given for drupal7
