Hi @animalejourbano
To bulk update this value, I would create a new page template where you can write and run some custom code.
This template would use the WP_Query / get_posts function to query the DB for all the posts you want to update.
Then, loop through all the posts and for each post, load the ACF value (get_field()), and then use the wp_update_post function to set the post_content with the ACF value.
Hope that helps.
Thanks
E
