Nitro is one of those themes that relies on just a local activation check to allow demo or plugin installation.

This method works since at least v1.2.5 and has been checked with v1.4.3 with success.

To null, edit the file wr-nitro/woorockets/includes/update.php

1) Around line 91ish find the code

        // Verify purchase code.
        $r = wp_remote_get( add_query_arg( $input, self::ENVATO_APP_SERVER ) );

ABOVE it add this:

        update_option( 'wr_download_token', $r['data'] );
        remove_filter( 'sanitize_option_nitro_customer', array( __CLASS__, 'validate' ) );
        update_option( 'nitro_customer', $input );
        wp_redirect( add_query_arg(
            urlencode( __( 'Thank you for choosing Nitro!', 'wr-nitro' ) ),
            admin_url( 'admin.php?page=wr-intro' )
        ) . '#registration' );


2) in the same file fund the function get_download_token() near the bottom of the file

After the opening curly bracket of the function add this:

if ( get_option( 'nitro_customer' ) ) {
return 'yep this is a token honest guv';
} else {
return false;

Now you can use any details to activate the theme and all plugins and demo content will be available to install.