Manually uninstall RSFirewall!
If for some reason the automatic uninstallation fails, follow these steps to manually remove RSFirewall! from your WordPress installation.
Locate your wp-content/plugins/ folder. Delete the folder named RSFirewall!.
Connect to your MySQL database and remove all of the _rsfirewall_ tables. For example, if your WordPress database prefix is "wp", remove all tables that start with wp_rsfirewall.
For instance, use this SQL script:
DROP TABLE `wp_rsfirewall_feeds`, `wp_rsfirewall_hashes`,`wp_rsfirewall_ignored`, `wp_rsfirewall_offenders`, `wp_rsfirewall_signatures`, `wp_rsfirewall_snapshots`