There are two ways to trash a post using Nelio’s Editorial Calendar.
Dialog for Editing Posts
If you click on a post, a dialog for editing it will pop up. As you can see in the following screenshot, this dialog includes a Trash icon in the lower left corner:
If you click on it, a new dialog asking you whether you really want to trash the post will pop up:
Unlike what happens with social messages, you can undo this operation. That is, if you trash a post, you can easily go to the trash (WordPress Dashboard » Posts » Trash) and Restore it.
Drag and Drop
Another option is to drag the social message and drop it on a Trash. To do that, just click on the post and drag the post around. Once the dragging begins, you’ll realize that there are new actions available next to the calendar, including a couple of Trash icons:
Just hover over one of these icons whilst dragging the post and drop it on them (as depicted in the screenshot above). This will trash the post, so, as before, the action can be undone.