To view or change bookmarks, click the BOOKMARKS button to toggle between displaying bookmarks and thumbnails. (Click the THUMBNAILS button to display thumbnails in place of bookmarks again)
Displaying the bookmarks, you can then activate, edit, add, and delete bookmarks (or often called outline) items.
Clicking any bookmark twice will expand or compact the bookmarks that are child (inside of, for example 1.10 is a child of 1. in the above screenshot) bookmarks of the selected bookmark.
Select a bookmark item, then right click to select an operation to perform on the bookmark. The following drop down will appear:
Click ADD to add a bookmark as a child to the selected existing bookmark. For example, to add a bookmark after 1.09, you would click 1., and click ADD. Clicking 1.09 and clicking ADD will add a bookmark as a child of 1.09, not as the next bookmark (as would be 1.10).
Type in the title of the bookmark and type in the page that you want the bookmark to link to. Then click OK and the bookmark will be added.
Click EDIT to edit the selected bookmark.
You will be able to edit the title of the bookmark as well as the target page of the bookmark.
Clicking DELETE will display the delete dialog.
Clicking YES will delete the selected bookmark.
Clicking the GOTO option when you right click a bookmark item will take you to the target page of that bookmark item in the PDF. For example, clicking GOTO on the 1.1 Sub 1 bookmark would take you to page 2.