// Open: /wp-content/plugins/wordpress-seo-premium/vendor/yoast/license-manager/class-license-manager.php
// Find code and comment...
// show notice if license is invalid
if ( ! $this->license_is_valid() ) {
if ( $this->get_license_key() == '' ) {
$message = '<b>Warning!</b> You didn\'t set your %s license key yet, which means you\'re missing out on updates and support! <a href="%s">Enter your license key</a> or <a href="%s" target="_blank">get a license here</a>.';
} else {
$message = '<b>Warning!</b> Your %s license is inactive which means you\'re missing out on updates and support! <a href="%s">Activate your license</a> or <a href="%s" target="_blank">get a license here</a>.';
}
?>
<div class="error">
<p><?php printf( __( $message, $this->product->get_text_domain() ), $this->product->get_item_name(), $this->product->get_license_page_url(), $this->product->get_tracking_url( 'activate-license-notice' ) ); ?></p>
</div>
<?php
}