Click the page you want to rotate in the left-side Thumbnail Panel, or press the Ctrl key and select multiple pages simultaneously, and then right-click the thumbnail(s) to select the "Rotate" option.
Alternatively, you can hit the "Page" button, enter the page number in the box to select a page or click the page thumbnail directly, and then you can click the button to rotate it clockwise or counterclockwise.
Keep pressing the Ctrl key and click multiple page thumbnails, and then you can click the button to rotate multiple pages at once.
Click the "File" > "Save" or "Save As" button to save the changes.
