Deleting the Solid Security Pro plugin via your site's WordPress dashboard will remove all Security settings and revert all to the default configuration once you re-install.
To delete the Solid Security Pro plugin, navigate to your WordPress dashboard, go to Plugins -> Installed Plugins -> Solid Security Pro, and deactivate the plugin. After deactivating, delete the plugin.
It's also recommended to double-check your database to ensure that all `itsec` tables are removed after deleting the plugin from your website's WordPress dashboard.