In order to convert PDF to EPUB, you need to use a converter that is available online or offline. I prefer to use online tools (if I have a good Internet connection). I also like that I can’t clog the laptop memory and use the program online. It is convenient for me to convert files in PDFChef. It's fast and free. In addition to converting I can edit files if I need to.
In your file menu choose “Make PDF” (or “Download PDF”) and check the “PDF file format” checkbox. In the popup, choose “File > Edit PDF using Adobe Acrobat.” The Acrobat Reader window will present itself in the menu bar. Choose “PDF > Get Info”. You should see the filename in this dialog box. Click on that number in the text box and change the file name accordingly. This is the filename your converter should use. Save the file as “PDF.ABR” and click on Save As. If your PDF is not there, go to your downloaded files tab and click on “Load” for “My Downloads”, then “PDF”. The Acrobat Reader and file icon will pop up. Click on them, and you can start the conversion/editing process. ’If you need assistance with editing: In the Acrobat Reader window, simply go to the page you want to edit and click on the edit.