Follow these steps to disable a WordPress plugin via WordPress:
1. Log in to your WordPress Admin/Backend portal. To do this, open up a web browser then type in yourdomain.com/wp-admin or yourdomain.com/wp-login.php into the address bar.
2. Once you have logged in, on the left-hand side, click Plugins.
3. This will bring up a list of all currently active plugins. To disable a WordPress plugin, go to the plugin you wish to disable and click the Deactivate link. A pop-up message will appear to advise that your plugin is now disabled. (To reactivate it, click Activate.)