Installed Module crash my site. How do I bring my site back up by uninstalling a module
In Drupal 8, try to removing the module from your module folder and run http://YOURSITENAME/update.php

or

Removing module via Database - In Drupal 8 it is a bit hard to remove a module.

I think the best way is to use Drush.

drush pm-uninstall module-name (machine-name)