Simple Install
1. Login to WordPress and go to Plugins > Add New > Upload
2. Upload nivo-slider.zip and activate
3. Start adding your sliders in the "Nivo Slider" menu that appears.

Manual Install
1. Upload the nivo-slider folder to your /wp-content/plugins/ directory.
2. Activate the plugin through the 'Plugins' menu in WordPress.
3. Start adding your sliders in the "Nivo Slider" menu that appears.