Due to some errors you can face few occasions when you become unable to login in to your wordpress account, so it becomes difficult to handle the plugins installed on it. Following is the procedure which allow you to handle your plugins without logging into wordpress dashboard.

Login to your website hosting server via FTP and change the names of folders of all plugins, for making things simple you can just add single character of your choice to these names. If the error is more critical and deactivating your plugins is not enough then its recommended to switch to the default theme. You can do this by changing the name of your currently installed theme as this will activate the default theme automatically.