The easiest way to install the plugin is to use the One-Click Install option
of the WordPress Plugin Manager.
Otherwise, install the spell-plugin.php file
in the 'wp-content/plugins' directory and the rest in a directory you create
called 'wp-content/spell-plugin.
The plugin must be enabled from the plugins
page, then ''you must visit the Spell Checker options page at least once''
before the plugin will be finally enabled. Follow the appropriate link in the
Spell Checker entry of the Plugins page.