如何从后端编辑wordpress页面

i have created a plugin that creates a page on activation. now i cant find a way to update the content of the page programitically i have been searching the internet for a while could not find an answer here is how i create a new page using my plugin

function some_function()
{
   $post_details = array(
      'post_title'    => 'Page title',
      'post_content'  => 'Content of your page',
      'post_status'   => 'publish',
      'post_author'   => 1,
      'post_type'     => 'page'
   );
   wp_insert_post( $post_details );
}
register_activation_hook(__FILE__, 'some_function');