Hi pasetti,
Thank you. ?? Would you be willing to explain a little more about the issue you’re having? Some plugins and themes have JavaScript-based features that require the JS to stay in the head. It can’t be moved without breaking the site. This is already mentioned in the plugin documentation on the FAQs page. If you want to keep the other features, you can use RS Head Cleaner Lite…it has everything this does without the JS to Footer feature.
I’m not sure what you mean about uninstalling it completely. This plugin doesn’t add anything to the database, and it uses no options so once you deactivate the plugin and delete it either through the WordPress Admin or through an FTP client, it’s gone, finito, done.
If you’re still having it show up in your site after that, you may need to clear your browser cache or delete any cache files created by caching plugins.