Unfortunately your notes/highlights won't be exported or printed with a PDF. The only way at the moment to export notes is with the Google Docs and Word add-ons. In both of these, click the menu and select Project references & notes:
Then select your project and you'll see a list of notes/highlights for the chosen project, with the option to open, insert or cite them.
Choosing the Insert option will insert the text of the note you've made, the text in the highlighted section and a citation for the reference: