If you are unable to login to wordpress and are seeing an error similar to:
*Warning*: Cannot modify header information - headers already sent by (output started at /home/example/public_html/wp-content/plugins/zopim-live-chat/accountconfig.php:20) in */home/example/public_html/wp-includes/pluggable.php* on line *1121*
You may have a plugin that is preventing wordpress from functioning correctly.
It possible to disable a wordpress plugin by logging into phpmyadmin, selecting your wordpress table, which is usually your username followed by _wp1.
For example, if your username was bob, your wordpress name might be bob_wp1
Once you've found your table, run the following query against your table.
UPDATE wp_options SET option_value = 'a:0:{}' WHERE option_name = 'active_plugins';
This will disable all active plugins, but will not delete or modify them.
You can also run a query through the command line.
Log in through SSH and execute the following commands.
root@example# mysql <database name>
Mysql> UPDATE wp_options SET option_value = 'a:0:{}' WHERE option_name = 'active_plugins';