You should have already followed the Storing user settings using arrays recipe to have options data ready for deletion, and the resulting plugin should still be active in your development site. Alternatively, you can get the resulting code (Chapter 3/ch2-page-header-output/ch2-page-header-output-v3.php) from the downloaded code bundle. You should rename the file ch2-page-header-output-v3.php as ch2-page-header-output.php, and have activated the plugin once before starting this recipe.