2. Select Thumbnails
3. Enable Selection by clicking on the Select button
4. Check boxes will appear on all the pages, and tapping or clicking on a page will now select it.
5. Select one of the options to Rotate, Delete, or Export the selected pages.
Tip: If using mouse, you can also right click on any page to perform any of the above actions. This will only affect the page that was right clicked though.
Merging PDFs, Images, and adding blank pages to existing PDFs
Reordering pages within a document