Unattach

Unattach is a very simple plugin which allows detaching images and other media from WordPress posts, pages and other content types.

As of WordPress 4.2 this functionality is built in. For previous versions, the only way to detach a media item from a post is to delete either the post or the media item. This plugin solves that by adding an ‘Unattach’ link below each media file in the Media Library admin list view.

Plugin by Outlandish