Bulk Actions is a WordPress plugin by esper van Engelen that adds new bulk actions to your admin panel on the posts, pages and users overviews. It works with custom post types.
Using this plugin, you can easily switch the post types of multiple posts at once, and other bulk actions are added dependent on user demand. The plugin relies on functionality introduced in WordPress 4.7.
Therefore it only works only with WordPress versions 4.7+, according to the author.
Change post type for multiple posts at once
Change post type to any other post type
Works for posts, pages and custom post types