Do one of the following:
Choose View - Slide Sorter, select one or more slides, and then drag the slides to another location. To select multiple slides, hold down shift and click on the slides. To create a copy of a selected slide, hold down Ctrl while you drag. The mouse pointer changes to a plus sign. You can also drag a copy of a slide into another open LibreOffice Impress document.
Choose View - Outline, select a slide, and then drag the slide to another location.
Choose View - Normal or Notes, select the slide preview on the Slides Pane, and then drag the slide preview to another location.
To temporarily remove a slide from your presentation, go to Slide Sorter, right-click the slide, and then choose Show/Hide Slide. The number of the hidden slide is crossed out. To show the slide, right-click the slide, and then choose Show/Hide Slide.