Write an article based on this "Visit Smallpdf.com Use your favorite browser to visit http://merge.smallpdf.com. Choose the documents you want to extract pages from. Edit your files and rearrange the order. Merge PDF."

Article:
Drag-and-drop your PDF (or multiple PDF files) into the drop area on the site. Switch to the "Page mode" (2.) on the site. Then you are able to see the single pages. In the area underneath each picture you find (right) the number of the document (move your cursor over the the number to see the title) and on the left side the page number. Now you can rearrange the order and choose the pages you'd like to extract and remove the remaining ones by clicking the X-symbol in the corner of an image. When you are done and the upload is completed you can create the final PDF by pressing the button below the preview area. A new PDF file will be created, automatically downloaded and you can find it in the download folder of your browser.