Calibre has had a book editing feature, since version 1.15. If you manage your ebooks in Calibre, just right click-click on the book and select "Edit Book".
If you have Calibre installed, but do not use it to manage your books, you can start the editor from the commandline with:
ebook-edit /path/to/your.ebook
One thing you should note however is that in an EPUB file a "page" depends on the rendering device, the font etc. A page-break can be "inserted", through page-break-*
styles associated with an element, and seem to be enforced through splitting of the HTML within different .html
files of the .epub
as well.
If a section of HTML contains enough text to require rending in multiple pages, it is difficult to speak about something like "removing the first page", as what is exactly contained on the first page is not constant even if the EPUB doesn't change.