If you are using a Macintosh you have a tool called Preview in your Applications folder. It appears to be a very simple tool for opening PDF files and pictures. If you take a closer look you’ll find that it has many tricks up its sleeves, including the ability to merge, rearrange, and delete pages of PDF files.
REQUIRED: MAC OS 10.5 or newer.
To rearrange the pages within a PDF file, simply drag them from their current location in the sidebar to the location you would like for them to be. (View this step.)
To delete one or more pages from a PDF file, select the page(s) in the sidebar, and choose “Delete” from the Edit menu. (View this step.)
Remember to save your newly merged, rearranged, or otherwise edited PDF by going to the Edit menu and selecting “Save.” (View this step.)
If you like what Preview can do with PDF files, you’ll love what it can do to edit your pictures! To try it out, open any image and look at the “Adjust” options in the “Tools” menu.
Updated June 19, 2017