Changing admin Textarea to integrated WP editor

by

Try Advanced Custom Fields and simply add a WYSIWYG editor.

Step 1
Step 1

Et Voila!
And Voila!

Displaying the input on the front-end

<?php
  /* Put the attachment ID in place of 999 */
  // Display
  the_field('yea', 999);
  // In case you need to don't want to display it right away
  get_field('yea', 999);
?>